ILO V6 User Manual Issue 17 - Otodynamics Ltd manual issue 17.pdf · ILO V6 Clinical OAE Software...

ILO V6User ManualIssue 17

User Manual for Echoport instruments

ILO V6Clinical OAE Analysis and Data Management

ILO V6 Clinical OAE Software Manual • Issue 17 • September 2015 3

ILO V6 User Manual

Issue 17 : September 2015

ILO V6 version v6.41.27.33 onwards

Doc Ref: MANV6-BK:17

Copyright Notice

No part of this publication may be copied by any means, translated or distributed to third parties without the express written permission of Otodynamics Ltd.

Copyright © 2015 Otodynamics Ltd. All Rights Reserved.

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4 ILO V6 Clinical OAE Software Manual • Issue 17 • September 2015

Contents

1 Introduction ................................................................................... 9

2 ILO CD and software installation ............................................... 112.1 MinimumPCspecifications ............................................................ 112.2 ILO CD ............................................................................................ 112.3 ILO V6 Software installation ...........................................................12

3 Main features of ILO V6 Clinical OAE software .......................... 143.1 General features .............................................................................143.2 OAE recording ................................................................................143.3 Advanced functions ........................................................................153.4 Analysis tools ..................................................................................153.5 Probe ..............................................................................................153.6 Data handling ................................................................................16

4 Making use of OAEs: Key points for clinical practice ................. 174.1 Recording OAEs .............................................................................174.2 Types of OAEs ................................................................................174.3 Middle ear factors ...........................................................................184.4 OAEs and the nature of sensory hearing loss ................................184.5 Interpretation of OAEs ....................................................................194.6 Differential diagnosis ......................................................................204.7 Special applications ........................................................................20

5 Initial setup ................................................................................. 21

6 Getting to know V6 software....................................................... 246.1 Introduction to the main screen ......................................................246.2 Screendatafields ..........................................................................266.3 Navigating around the program ......................................................276.4 File menu ........................................................................................276.5 Tests menu .....................................................................................296.6 Reports menu .................................................................................296.7 Data management menu ................................................................306.8 Help menu ......................................................................................30


7 Preparing for a test ..................................................................... 317.1 Selecting the Test Mode .................................................................317.2 Entering patient details ...................................................................327.3 Using a worklist ..............................................................................337.4 Selecting the test type ....................................................................35

8 Performing a TEOAE test ........................................................... 368.1 Choice of Stimulus ..........................................................................368.2 Checkfit ...........................................................................................388.3 Data collection ................................................................................408.4 Checkfitandtestingstimuli .............................................................418.5 Test termination ..............................................................................428.6 OAE Response window ..................................................................448.7 Response Waveform window .........................................................468.8 Saving and printing the data ...........................................................488.9 Printingconfiguration ......................................................................548.10 Formats of data stored ...................................................................56

9 Spontaneous OAEs (SOAEs) ..................................................... 599.1 What are SOAEs? ..........................................................................599.2 How SOAEs can affect OAE measurements ..................................609.3 Detecting SOAEs ............................................................................609.4 Performing an SOAE search ..........................................................61

10 Performing a DPOAE test........................................................... 6210.1 Choice of Stimulation ......................................................................6210.2 Checkfit ...........................................................................................6310.3 Setting of stimulus tones ................................................................6410.4 Data collection ................................................................................6510.5 DP Spectrum ..................................................................................6710.6 OAE response (SNR) display .........................................................6810.7 Test termination ..............................................................................6810.8 OAE Response window for DPOAEs .............................................6910.9 Saving and printing the data ...........................................................71

11 Advanced DPOAE measurements ............................................. 7211.1 Changing stimulus parameters for DPOAEs ..................................7211.2 Multi-level DPOAEs ........................................................................7311.3 Advanced DP Growth functions ......................................................74


12 Binaural OAE measurements - introduction ............................... 80

13 Regular binaural measurements ................................................ 81

14 Advanced binaural OAE measurements .................................... 8314.1 Contralateral TE suppression test ..................................................83

15 Reviewing data ........................................................................... 9315.1 Examine/Compare data ..................................................................94

16 Setup options.............................................................................. 9616.1 OAE System Setup .........................................................................9616.2 Stims (including setting new DPOAE high frequency range) .......................97

16.3 Start/Stop/Score .............................................................................9916.4 Environment .................................................................................10016.5 Exports .........................................................................................10216.6 Probes ..........................................................................................103

17 Test protocols and stop logic ................................................... 107

18 Reporting .................................................................................. 11018.1 Operational statistics .................................................................... 111

19 Data management options ....................................................... 11219.1 Backup database... ....................................................................... 11219.2 Archiving functions ....................................................................... 11319.3 Data transfer/import functions... ................................................... 11519.4 Importdatafiles... ......................................................................... 11819.5 Echocheck functions ..................................................................... 11919.6 Database maintenance .................................................................12119.7 Re-Export to: ................................................................................124

20 Help menu ................................................................................ 12520.1 Email Dealer or Otodynamics .......................................................12520.2 Register a new license .................................................................12520.3 About ............................................................................................125

21 Networking ................................................................................ 12621.1 LAN client/server installation ........................................................12621.2 Independent single desktop installation that periodically transfers data to an ILO V6 ‘data bank’ via the LAN ....................................127


22 Mode of operation..................................................................... 129TEOAE Tests .........................................................................................129

23 Response detection .................................................................. 132 ConfidencelevelsinDPOAEtests ...............................................133 Confidenceformultiplefrequencypoints .....................................133 ConfidencelevelsinTEOAEtests ................................................134 Conclusions ..................................................................................136

24 Index ......................................................................................... 137


1 Introduction

1.0.a ILO V6 Clinical OAE software opens up new windows on the cochlea. Designed by the originators of OAE technology and based on 40 years of experience with OAEs, V6 software is an expanding suite of carefully engineered OAEinvestigationalfacilitieswithprovenclinicalorscientificvalue.Italsoincorporates advanced data management services.

1.0.b To gain the most clinical insights from V6 software, you need to keep in mind the source of OAEs. The outer haircells of the organ of Corti are responsible for healthy ears achieving high sensitivity and good frequency selectivity at low stimulus levels. They do this by assisting the stimulus energy to pass along the basilarmembranewithoutloss–sothatspecificfrequenciesreachthesensorycellsatspecificplaces.Thisprocessisoftentermedthe‘cochlearamplifier’,butit’snotaperfectamplifier.Duringitsoperationitgeneratessomedistortionand also allows stimulus frequency energy to escape. Both reach the middle ear as vibration and this creates secondary sounds in the ear canal. Sometimes outer hair cell energy is released without external stimulation, giving rise to spontaneous sound emission.


1.0.c The aim of clinical OAE measurements is to establish the status of the cochlea. However, as sound stimulation and the otoacoustic responses must both pass through the middle ear, a healthy middle ear is necessary before cochlear status can be established. Although NOT a measure of middle ear status, unexpected absence of OAEs indicates that the middle ear status should be examined. Only if middle ear status is normal and technical conditions for recordings are adequate can an absence of OAEs be taken as evidence of abnormal cochlear function.

1.0.d To ensure your hardware is functioning correctly, it is important to conduct regular weekly system checks. In exceptional circumstances, either an equipment fault or failure to comply fully with the instructions in this manual may result in unreliable test results. Results with total OAE responses greater than 40dB SPL should be considered highly suspect and not to be relied upon.

1.0.e Strong OAE responses are normally obtained from healthy ears with normal hearing thresholds. The strength of OAE recorded depends on the stimulation applied. Please refer to the literature on OAEs before changing stimulus settings in ILO V6, as this could change the sensitivity of the instrument to hearing loss. Please also note that OAEs do not provide a replacement for the audiogram and hearing threshold cannot be reliably estimated from OAE measurements. Auditory pathology can affect retrocochlear function and also rarely inner hair cell sensory function. Both can result in hearing loss without loss of OAEs.

1.0.f OAEs should therefore by viewed as one important part of the audiological diagnostic test battery.


2 ILO CD and software installation

2.1 Minimum PC specifications2.1.a Processor Pentium III 1GHz or better

2.1.b Operating System Windows 10, 8, 7 and Vista

2.1.c RAM 1024MB minimum

2.1.d Hard Disk 50MB minimum free

2.1.e CDR / DVDR Recommended for database archiving and backup

2.2 ILO CD2.2.a Prior to software installation, close all application programs running on your PC.

2.2.b Insert the ILO V6 CD into your CD-ROM drive. The CD will start automatically and a menu will appear, presenting several options. Select the options using a left mouse click. If the CD does not auto-run, click Start > Run > Browse and select Run.exe.


2.2.c Install ILO V6 - begins the ILO software installation process.

2.2.d Manuals - opens a sub menu, which gives the option to view the different ILO software manuals. Manuals are in PDF format and require a reader to view.

2.2.e Browse CD - opens the CD so the contents can be viewed.

2.2.f Visit Website - opens the Otodynamics web site (your PC will need to be connected to the internet).

2.2.g Register - please register this software so that we can keep you informed of updates from time to time.

2.3 ILO V6 Software installation2.3.a TherearedifferentwaystoinstallandconfigureILOV6,whichrequiredifferent

installation procedures.

• As a Desktop or Network server version

• As a network client only version

2.3.b For further information about Networking options available, see the Networking section later in this manual.

2.3.c For standard installations follow the instructions below:

• Select Install ILO software from the CD menu.

• Follow the on screen instructions to proceed with the installation.

• You will be asked to enter a password – this will be found on the CD sleeve.


• If use of EZ•Screen 2 is required, ensure the box is checked to include this program in the installation process.

• If the program requests a PC re-start, accept this.

• Following installation, an ILO V6 icon will be placed on your PC desktop. (If selected an icon for EZ•Screen 2 will also be present)

2.3.d Note: Please refer to your Echoport Manual for instructions on connecting

your hardware and installing any necessary drivers.


3 Main features of ILO V6 Clinical OAE software

3.1 General features • User-friendly Windows-compatible TEOAE and DPOAE clinical software

• Easy installation

• Flexible database management

• Operation with new and classic Otodynamics DP Echoport products

• Full Windows compatibility - runs on Windows 10, 8, 7 and Vista

• Password protected user logins and two levels of user operation

• Automatic program statistics collected

• Easy to read and interpret reports

• User programmable automated stop criteria

3.2 OAE recording

3.2.1 TEOAEs

• Quick Screen and Standard ILO nonlinear recording

• Tone pulse stimuli

• Adjustable stimulus intensity

• Real-timestimulusmonitoringin‘Checkfit’andduringtest

3.2.2 DPOAEs

• DPgram with preset and custom selected stimuli

• Programmable level, level ratio, frequency ratio, points/octave, frequency range, manual/automatic/intelligent frequency progression


• Total DP power assessment

• DP growth rate analysis

• True time domain averaging and noise statistics

• Signal-to-noise assessment against TWO standard deviations from mean noise level

3.3 Advanced functions • Powerful ‘synchronised’ spontaneous emission search to reveal latent

Spontaneous OAEs

• DP Growth analysis

• Binaural TEOAE and DPOAE measurements

• Contralateral TEOAE suppression analysis

3.4 Analysis tools • TEOAE, full cross correlation, frequency analysis with reproducibility and

signal-to-noise data

• Examine/compare feature for TE-TE and TE-DP

• Response subtraction analysis

• Half-octave OAE power assessment

• Detailed spectrum analysis

• Full data table provided

• UserconfiguredASCIIoutput

• Waveform analysis

3.5 Probe • Smart probe technology - carried calibration and usage data

• ILO probe design - proven and improved in 15 years of service

• Easy to use probe test with pre/post test comparison


3.6 Data handling • Fully searchable patient database with reports

• ILOstandardDTAandDPGfileswrittenandread

• Exportable data to OZ, Hi*Track, XML, ILOV5, Excel and ASCII (user selectable data elements)

• Import of data from other V6 or EZ•Screen sites

• Integration of multiple sites, testers and machines into one database

• Ability for distributed deployment across a network

• Additional backup analysis with traditional ILOV5 software

• Automatic tracking of patients through testing and assessment

Note: Not all features listed are available for all Echoport models. Please

check with your hardware manual.


4 Making use of OAEs Key points for clinical practice by David T. Kemp

4.1 Recording OAEs4.1.a Advanced OAE techniques need a sound attenuating booth, but useful OAEs

canbemadeinaquietofficeenvironment.Backgroundroomnoise levels of 40dBAorbelowarerecommended.Agoodprobefithelpsblockoutexternalnoise, although this effect is minimal with neonate ears. Short bursts of more intense noise (e.g. speaking to the patient, or a cough), which can be detected and rejected by the instrumentation, are less troublesome than continuous or reverberant sounds. Patient movement is also not a problem with OAEs provided it does not result in cable-rub noise. Jaw action, swallowing and vocalisations cause ear canal noises, which can prevent good OAE recordings.

4.1.b Patency of the ear canal is essential for successful recordings. Obstruction by waxinolderpatients,orbyfluidorbirthdebrisinneonates,orbycollapseofthe canal in the latter, prevent OAEs from reaching the ear canal and are major causes of OAE recording failure. Sleep and sedation have minimal effects on OAEs.

4.2 Types of OAEs4.2.a There are two widely used OAE measurements: transient evoked OAEs

(TEOAEs) and dual-tone evoked distortion product OAEs (DPOAEs). DPOAE measurements are better suited to advanced clinical investigation on adult patients,eventhoughDPOAEanalysisiscomplexandinterpretationisdifficult.TheDPtechniqueismoreflexibleandpotentiallymorepowerfulthanTEOAEanalysis, having a wider useful frequency range. Waveform-based TEOAE measurements, as originally used in universal newborn hearing screening programmes, are also useful as a sensitive initial screen prior to full clinical examination. TEOAEs are also more sensitive to cochlear status changes manifested in subtle changes in the TEOAE waveform. DPOAE instruments can be used for screening with an appropriately low stimulus level (e.g. 65/55 dB SPL).


4.3 Middle ear factors4.3.a OAE detection is affected by conductive losses and OAEs will be absent if

there is effusion, glue, otosclerosis or ossicular dislocation. Moderate negative pressure and tympanic perforations not exceeding 30% result in the attenuation of only the lower frequency OAEs. Grommets do not greatly affect OAEs. Absent OAEs can reappear following effective middle ear treatment or surgery if the residual conductive loss is very small and the cochlea is normal. Large and unusual ear canals and perforations can disturb stimulus delivery by ‘ringing’ and so prevent successful recording.

4.3.b This does not arise with neonates, but their ear canals are extremely small and this needs to be accommodated in the selection of probe size and stimulation intensity.

4.4 OAEs and the nature of sensory hearing loss

4.4.a OAEs come exclusively from outer hair cells which do not themselves activate primaryauditorynervefibres,yetastrongrelationshipexistsbetweentheabsenceofOAEsandhearingloss.Thisforcesaredefinitionoftheterm‘sensory hearing loss’.

4.4.b Sensory transmissive loss canbedefinedashearinglossresultingfromdysfunctionofoutersensoryhaircellgroup.Absenceofthe‘cochlearamplifier’allows natural damping to remove most stimulus energy from the cochlear travelling wave and lowers the resolution of the cochlear imaging mechanism. Inefficienttransmissionofexcitationtotheinnerhaircells(IHCs)causeslossofhearing sensitivity and frequency selectivity. Since there remains a pathway for stimulation to reach the IHCs, profound hearing loss cannot be caused by outer hair cell (OHC) dysfunction alone. Total OHC failure is estimated to cause no more than 60 dB hearing loss. Loss of OAEs with a normal middle ear indicates sensory transmissive loss.

4.4.c Sensory transduction loss canbedefinedashearinglossresultingfromfailure of inner hair cells to respond and activate the synapsed auditory nerves. This could give rise to any degree of hearing loss from mild to profound since the auditory nerves themselves have no sensitivity to sound simulation. Loss of frequency selectivity would not necessarily accompany threshold elevation in a pure sensory transductive loss, and OAEs would be normal.


4.4.d It is clear from the high correlation between sensory loss and OAE absence that most sensory losses are of the sensory transmissive type. This makes sense, as the outer hair cell mechanism is both highly specialised and highly vulnerable to degradation by excessive noise, anoxia or ototoxic agents. OHCs selectively amplify weak stimuli which would otherwise fall below the threshold for IHCs to trigger a neural response and as a consequence the symptoms of sensory transmissive loss necessarily include loudness recruitment in addition to threshold elevation and reduced frequency selectivity.

4.5 Interpretation of OAEs4.5.a The presence of robust evokeable OAEs across the key speech frequency

range (1.0 - 4 kHz) indicates a useful degree of normal function in both the middle ear and cochlea and further indicates that speech and language development will not be greatly impeded by peripheral auditory dysfunction. For clinical purposes it is useful to record OAE status as a function of frequency, averaged over 1/2 or 1/3 octave frequency bands. Higher resolution has little physiological meaning.

4.5.b The absence of OAEs without middle ear pathology or acoustic obstruction strongly indicates sensory transmissive hearing loss. Depending on the type and intensity of stimulation, OAEs can reveal threshold elevations as small as 20 dB HL and the frequency ‘resolution’ of OAEs can be as good as 1/2 octave. The amount of threshold elevation cannot be predicted with any useful accuracy, but if DPOAEs are present with TEOAEs absent, this suggests mild to moderate loss only.

4.5.c OAEs are normally very stable with time and are valuable as a sensitive monitor of changes in cochlear (and middle ear) status over time, e.g. in relation to sudden hearing loss, Ménière’s disease or noise trauma.

4.5.d Although OAEs can differ enormously between healthy ears they are usually quite similar in the left and right ears. Substantial left-right differences may therefore indicate pathology.


4.6 Differential diagnosis4.6.a OAEs are expected to be present in sensory transductive, neural, central and

psychogenic hearing losses. OAEs can be either present or absent with 8th nerve tumours, depending on whether the cochlear blood supply has been compromised. If present, OAEs indicate the possibility of hearing recovery with a conservative surgical approach.

4.6.b OAEs are pre-neural responses indicating healthy cochlear status and cannot be used to detect sensory transductive or neural hearing losses. With neonates, the absence of an OAE response in clear dry ears should be treated as a strong risk factor for sensory hearing impairment. However, other risk factors need to be considered before presence of an OAE is taken as evidence of normal hearing. Hyperbilirubinemia or any risk of neurological damage requires that an ABR test also be conducted.

4.6.c Auditory neuropathy is indicated by the presence of normal OAEs but the absence of normal ABR responses. In such rare cases, the application of hearingaidswithhighamplificationmaybecounterproductive.IninfantsbothABR and OAE testing should precede hearing aid selection.

4.7 Special applications4.7.a OAEs can be slightly depressed by contralateral noise stimulation if the medial

cochlearefferentsystemisoperational.Thesignificanceoftheabsenceofthiseffect is not clearly understood but may help clarify the nature of certain neural pathologies.

4.7.b The objective nature of OAEs can be useful in the investigation and management of inorganic hearing loss by demonstrating normal cochlear function to the patient.

4.7.c Serious tinnitus is almost never associated with OAEs, but rather with their absence. Spontaneous OAEs can sometimes be perceived as tinnitus and occasionally cause unnecessary anxiety. Typically in such cases hearing threshold is normal and the tinnitus is mild, tonal and easily maskable by noise. Patients can be reassured by the objective demonstration of spontaneous OAEs.


5 Initial setup

5.0.a Connect the Otodynamics OAE hardware to your PC using the cable provided. Double-click on the ILO V6 icon created on your Windows desktop to run the ILO V6 software. You will be required to enter a license key when running thesoftwareforthefirsttime.Thelicense key can be found on the CD and/or documentation accompanying the software. The license key may be entered using upper or lower case letters.

5.0.b The Initial setup options screen is displayed.

5.0.c ILO V6 can be installed to run OAE tests or as a data manager for OAE data. If you are installing a USB system set the TypefieldintheOAE Instrument box to read Echoport USB OAE. If you are planning to use V6 as a data manager then set Type to Otoport viewer.

5.0.d The User and Facility detailscanbeenteredatthispoint.Itisimportanttofillthefieldslistedinaboldtypeface,asthesearemandatoryfields.TheFacility IDisaunique3-characteridentifierthatcanbeusedtoensurethatdatacollectedatdifferentsitescanbeeasilyidentified-youmaychooseanythreecharacters for this ID. The User/Operator IDisaunique3-characteridentifierfieldthatcanbeusedtoensurethattestsperformedbyaparticularusercanbeeasilyidentified(wesuggestthattheuser’sinitialsareused,ifnecessaryaddinga character to total three). The Global Site Name (GSN) is a unique 3-character hardwareidentifierthatensuresthatdatafilescollectedonaparticularILOsystemcanbeeasilyidentified.TheGSNwillbefoundontheCDlabel,with


theOAEhardwareserialnumber.Itispossibletofilterpatientandtestdatausing any combination of User/Operator, Instrument GSN and Facility ID. After enteringdetailsinthenecessaryfields,click<OK> to enter ILO V6.

5.0.e Maximise the ILO V6 window if necessary.

5.0.f If you are installing V6 for use with an Echoport but have not connected the hardware with the cable provided, the error message below will be displayed. In this event, connect the hardware and retry.

5.0.g If you see this message and you are installing V6 to manage Otoport data go to File > Setup Options > OAE system and set OAE System type to Otoport Viewer / Training Mode.


5.0.h On subsequent ILO V6 sessions, an ILO Operator Login screen appears.

5.0.i New operators can be added by entering the relevant details in the User Name,ForenameandIDfields,selectingUser or Advanced User privileges andclickingonthe<Add New User> button. Passwords may be entered if required by your protocol. The User/Operator can then be selected from the pull-down menu. Note that users do not have full access to menu options, thereforedisablingareaswhichincludeimportantconfigurationsettings,whichshould only be set by fully trained staff. All necessary intervention by a user can be accessed from the main screen. There are buttons to access the probe calibration check area and to do data downloads and transfers.

5.0.j Please remember to set the various directories to your preferred paths before you start testing. This is especially important if you intend to create and export records such as OZ SIMS, Hi*Track, .XML, .CSV, ASCII or GDT(option)files.Directories can be changed from the default paths via File > Options > Export/Import.


6 Getting to know V6 software

6.1 Introduction to the main screen

6.1.a The main screen is structured to present various textual, graphical and numerical data in an organised and digestible format. The menu bar (below the title bar) gives access to many layers of options and functions via six main drop-down menus; these are accessed with a mouse or by pressing the Alt key whilst holding down the underlined key in the menu bar title.

6.1.b To the left of the screen are three stacked panels with tabs labelled This Patient, Worklist and Review data. Clicking on the required tab will reveal the panel, giving access to further options and data.

6.1.c The Test data box sits to the left of centre-screen and details information about the test performed on the current patient being tested or reviewed. The patient details are displayed in the This Patienttab.The<Start Test...>,<Start Bilateral Test...>,<Print>and<Save> buttons sit below the Test data box. The functions are greyed out when inactive.


6.1.d The Stimulus window displays the click stimulus presented to the ear in ‘Checkfit’ mode, showing the magnitude of the stimulus with time.

6.1.e In TEOAE mode the Response Waveform graph shows the magnitude of the complex TEOAE waveform with time.

6.1.f The OAE Response window displays the level of OAE and the level of noise recorded in decibel sound pressure level against frequency. There are severaldisplayoptionsavailableforthispanel,specifictoTEOAEandDPOAErecordings. Please see the OAE Response window sections under Performing a TEOAE Test and Performing a DPOAE Test.

6.1.g To the right of the OAE Response window is the noise rejection level slider. This is used to set the level for the rejection of noisier data samples. The associatedfieldstotherightdisplaythenumberofsampleswithnoisebelowand above the level set by the noise rejection level slider (Nlo and Nhi) and afigurewhichindicatestheactualrejectlevel.AlsointhistableareothermeasurementsspecifictoTEOAEandDPOAErecordings.ForTEOAEdatathewave Reproducibility and stimulus Stabilityfiguresaredisplayed.ForDPOAEdata the ratio between F1 and F2 is indicated. These features are discussed later in the manual.

6.1.h The Numerical Data panel toward the bottom right of the screen shows technical information regarding the test performed, including the stimulus levelused,theOAEresponsepowerandthetesttime.ThedataisspecifictoTEOAE and DPOAE recordings.

6.1.i Along the bottom of the screen is the Status Bar. The protocol setting mode is shown here, along with the instrument GSN, the user 3-character ID and the export status. It is possible to hot swap between protocol modes and log on as different users by clicking the mouse on the relevant area.

6.1.j Note: When using Echoport USB systems and testing neonates, it is

important to set the protocol mode to neonatal screening or neonatal diagnostic. This will ensure the correct stimulus intensity is delivered to the patient. When in neonatal mode, the status bar changes to yellow.


6.2 Screen data fields 6.2.a Nlo : number of data samples (sweeps) accepted and processed. Data is

accepted when the noise level is below the noise reject level set

Nhi : number of data samples (sweeps) that have been rejected. Data is rejected when the noise level is above the noise reject level set

Repro : whole band reproducibility %

Stab : during test - displays the current stimulus stability status; post test - represents stimulus status at test termination

Rej : noise rejection level mPa

Resp dB : relative strength of the absolute response level in dB SPL

Noise dB : relative strength of the noise after averaging in dB SPL

Stim dB : peak equivalent stimulus level

DP Level : total DP power dB SPL

L1 and L2 stim : the DP stimulus levels used in dB SPL

F2/F1 : the ratio between DP stimulus frequencies used

Test time : total recording time in seconds

Status : current type of activity

6.2.1 Bottom panel of screen6.2.1.a Mode : test type currently selected (diagnostic, screening etc.)

GSN : GlobalSiteName(hardwareidentifier)

XXX : Operator ID

Ex=OFF : export option (Ex=OFF, OZ, Hi*Trk, CSV, XML, Ascii)


6.3 Navigating around the program6.3.a Navigation around the program can be achieved using a combination of hot-

keys, the mouse and drop-down menus. Hot-keys for particular functions are denotedbytheletterthatisunderlined.Certainfunctions,suchas<Cancel> and<Continue>, can be selected by pressing the Esc or Enter keys. Alternatively, use the mouse to highlight and click on the appropriate tab, button orfield,orpull-downandselectedoptionsfromthetoolbar.Themainmenuoptions (File, Tests, Reports, Data Management, Help) can also be selected by pressing the Alt key together with the key underlined.

6.3.b A summary of menu bar options follows. Many of the menu items are explained in full detail in later sections of this manual.

6.4 File menu

6.4.1 Examine/Compare data6.4.1.a This item is selectable when a test result is being reviewed and displayed on

the main screen. Examine/Compare data provides a method of displaying two patient test results at a time, side by side on the screen. (See Reviewing Data section for more information).

6.4.2 Print6.4.2.a Thisopensawindowonthe<Print> button which gives various printing options

for the current patient.

6.4.3 Print setup6.4.3.a The printer properties are set up here.


6.4.4 Options

6.4.4.a This is a major section, allowing you to choose your OAE system, set your own testingcriteria,registerandcalibrateprobesandspecifylocationoffilescreatedwithin the software. There are pre-set values for stimuli, protocols etc., but you may wish to change these when you are familiar with the software. (Please see Setup Options for full details).

6.4.5 System Checks6.4.5.a Select<Run Diagnostics> to run all equipment system checks. These can be

printed, or sent by email to Otodynamics.

6.4.6 Logon as different user6.4.6.a Select this to change user or add new user.

6.4.7 Exit6.4.7.a Select this to exit.


6.5 Tests menu

6.5.a The Tests menu provides a list of test options and a short-cut to the stimuli setupscreen.Thefirstitem‘Start test’ default action activates a secondary menuwhereyoucanpre-selectthetestwhichcommenceswhenthe<Start Test> button on the main screen is pressed.

6.6 Reports menu

6.6.a Thismenuoffersanumberofpatientreportoptions.Reportscanbefilteredbyoperator, instrument, facility, and date.


6.7 Data management menu

6.7.a The Data management menu provides facilities for data backups, archiving and managementoffilesfromotherILOsystems.

6.8 Help menu

6.8.a The Help menu enables you to search for help on any topic in the V6 manual and provides facilities for emailing your dealer or Otodynamics, registering a new software license and viewing the Otodynamics website. The About option provides information on the current ILO V6 software version.


7 Preparing for a test

7.1 Selecting the Test Mode

Always set mode to Neonate when testing newborns or very young infants.

7.1.a The currently selected Test Mode is shown at the bottom of the screen. The four test modes available are Neonate Screening, Neonate Diagnostic, General Screening and General Diagnostic. Always choose a Neonate mode when testing a newborn or very young infant. If a neonate is tested while in one of the GeneralModes,thestimuluslevelduringCheckfitwillinitiallybetoohigh.Wedo not recommend that you use the automatic adjust function to correct for this.

7.1.b The Test Mode can be changed in File > Options > Start/Stop/Score (shown above) or by a left-click on the Mode= box at the bottom of the screen, and then choosing the correct Mode. To help identify when neonatal mode has been selected, the status bar at the bottom of the page is coloured yellow.


7.2 Entering patient details7.2.a The demographic details of the patient are

recorded in the This Patient panel. The minimum requirement needed to run a test is to enter the Family name. If an ID number is not entered at this stage, an automatic ID number is created at the end of the test. After saving the test and the Which ear? window is closed, an Automatic ID box appears which allocates an automatic ID number. This can be edited prior to accepting the ID and is added to the ID number fieldintheThis Patient panel.

7.2.b Fields for Mother’s Name, Weight, Time of birth, Status and Multiple births are only available when in one of the two Neonate Modes. Please refer to the EZ•Screen Manual for full details.

7.2.c Further patient details can be entered by selectingthebuttonnextto<Start New Patient> and entering Patient and Mother/Guardian’s details.

7.2.d Also, risk factors and additional test history can be added. Family name and test ID are locked, but can be edited by selecting the lock to the right of the Family name. However, the Family name and ID cannot be changed if another record exists with the same data.


7.3 Using a worklist7.3.a Tohelpwithefficiencyandreduceappointmenttimes,itmaybeusefultouse

the Worklist feature. This allows you to enter patient details into a worklist and select them for testing as and when required. If your screening programme involves using a number of ILO systems which are networked in some way, then you should consider using worklists as a method of administrating testing. The use of worklists allows a central administrator to distribute details of the patients to test to each ILO system and then to receive the test results from each machine for collation. Each user can pick up a list of patients to test at the start of each day, perform the tests and then send the results to the administrator. Patient lists can be obtained, and results stored, over a local area network.

7.3.1 Editing the Worklist

7.3.1.a Click<Edit the worklist> button to open the editing window. Input patient detailsintotherelevantfieldsbyclickingontheFamily namefieldthenusingthetabkeyormousetomovebetweenfields.Family name and ID number are keyfieldsandbothmustbecompletedbeforethepatientcanbemovedtothelistbyclickingthe<Update> button. Please note that an Automatic ID option is not available with the worklist.

7.3.1.b Note: The‘Sex’fieldmustalsobecompleted.Itispossibletosavea

patienttotheworklistwithoutthisfieldfilledin,butitwillnotbepossible to save the record to the database.


7.3.2 Editing/Deleting Patients7.3.2.a Working from the Edit the worklist window, move the cursor line to the patient

tobeedited/deleted.Thepatient’sdetailsnowappearinthelabelledfieldsandcan be edited; alternatively the patient can be removed from the list by clicking the<Delete>button.Afterediting,clickthe<Update>button,followedby<OK> and the edited list will appear as the Worklist.

7.3.3 Selecting a Patient7.3.3.a Click on the Worklist tab to open. Select the

operator from the drop down list arrow to the right-hand side of the Operatorfield.Movethecursor to the patient to be tested, then click <Select this patient>. The selected patient will appear in the This Patient panel ready to start testing.

7.3.4 Importing worklists 7.3.4.a The<Import..> button allows worklists to be

imported from third-party tools. The format of the importfileisthestandardCSVcommadelimitedformat. This can be written by spreadsheet applications.Theorderofthedatafieldshastobethe same as that displayed on the worklist form (i.e. Family name, ID number, forename etc.). Only the Family name and ID number have to be present,alloftheotherfieldsareoptional-butifpresent they must be in the correct order with all precedingfieldsalsopresent).Hereareacoupleof examples of the suitable worklists to import...

Brown,1234 Smith,3366

or a more detailed list would be...

Brown,1234, Michael,James,Male Smith,3366,Joanne,Mary,Female

7.3.4.b Thesefilesshouldbesavedwithasuitablefilename,ensuringthatthefilenameextensionis.csv.Duringtheimportyouwillberequestedtonavigatetothisfileusingastandardwindowsfileselectiondialoguebox.Onceselected,thedatawill be added to the list shown in the worklist.


7.4 Selecting the test type

7.4.a Choose the type of test you wish to perform from the Tests menu - TEOAE, DPOAE, DP Growth or Spontaneous. Please refer to the sections Advanced DPOAE measurements - multi-level DPOAE, Spontaneous OAEs and Binaural OAE measurements for further information on these test types.


8 Performing a TEOAE test

8.0.a Connect a probe. Fit an appropriately sized probe tip and insert the probe in the ear to be tested. Ensure that the correct Test Mode and Test Type have been selected, as described previously in Preparing for a test.

8.0.b Transient evoked OAEs are highly individual responses which are very sensitive to changes in cochlear status.

8.1 Choice of Stimulus8.1.a To change the Stimulus type, either press Ctrl+S, or select Tests > Stimulus or

File > Options > Stims.

8.1.b Choose Quickscreen for the most rapid overview of cochlear status. This stimulus is repeated 80 times per second, and its energy is biased towards midfrequencies. It implements the nonlinear stimulus procedure for artifact rejection. This stimulus is extensively used for newborn hearing screening but is equally useful for the initial OAE test. Quickscreen should not used if OAEs below 1kHz are of interest. Each accepted sweep (NLo) averages the responses to sixteen stimuli (8 for the A waveform and 8 for B. Note: The A and B waveforms are two interleaved measurements combined in a single OAE result).

8.1.c Select Nonlinear click stimulation for clinical documentation of TEOAEs. This uses a plain click stimulus (80 microsecond drive signal) repeated 50 times per second - resulting in a 20ms response window. Each accepted sweep (NLo) averages the responses to eight stimuli (4 for the A waveform and 4 for B).

8.1.d The differences in stimulus, response window, stimulus repetition rate and adoption of the non-linear stimulus method mean that Quickscreen, Nonlinear and Linear modes may yield different responses from the same ear. In particular because Quickscreen records twice as many stimulus responses within each sweep Quickscreen will show lower noise levels for the same sweep (NLo) count.

8.1.e The Linear mode of TEOAE is not for regular clinical use. Normally NON-linear TEOAE is used (as in Quickscreen) as this provides a much higher immunity from stimulus artifact contamination. With Linear TEOAE some stimulus energy is present mixed with the TEOAE especially at normal and higher stimulus levels. It must not therefore be used for screening.


8.1.f Linear TEOAE is a specialist OAE measure. The Linear measure can record weaker TEOAEs and TEOAEs at lower stimulus level. This is because some TEOAE is lost in the normal nonlinear measuring process.

8.1.g Linear can be useful when tracing TEOAE to very low stimulus levels. Also when looking for small changes in TEOAE. If TEOAE response ‘1’ is subtracted from TEOAE response ‘2’ from the same ear and obtained with the same probe fittingthenthestimulusartifactwillbecancelled.Thedifferencesbetweenthetwo responses will be clearly seen. This technique has been successfully used to observe the effects of contralateral noise on OAEs (suppression).

8.1.h Warning: Linear TEOAE must NOT be used for routine screening and

diagnostic applications.

8.1.i Spontaneous OAEs are described in the next section.

8.1.j Select Tone pip only after performing a click TEOAE. Tone pip TEOAEs allow maximum stimulus energy to be concentrated on a selected frequency band.

8.1.k Clickonthe<Start Test> button to begin a test.


8.2 Checkfit8.2.a If the Checkfitpeak stimulus level is within the range 84 ± 3 dB pe (by default),

the arrow on the peak stimulus level meter should point to the green region of the scale. The target stimulus level can be changed via the File > Options > Stims menu.

8.2.b The stimulusshouldhaveaclean,clearpositiveandnegativedeflectionfollowedbyaflatline.Aflatorpoorstimulusmayindicatethatthetiporcouplertubes are occluded by fluidordebris (please refer to the section detailing probe care). Too much “ringing”, or oscillation, in the latter part of the stimulus waveformcouldindicatethatthetipisnotproperlyfittedtotheprobe,thetipisnot providing an adequate seal in the ear canal or the probe is angled towards the ear canal wall. In some adults, the “ringing” may be physiological and causedbyaparticularearcanalgeometry.Refittheprobeandensurethatyouhavethebestfitpossible.Thestimulus spectrum should be a smooth, rounded curve. A jagged stimulus response in the low frequencies or a sharp peak in themid-frequencyrangeindicateabadprobefit.Inlongeradultearcanals,there may be a dip in the stimulus spectrum measured at the probe caused by standing waves in the ear canal. A trough in the stimulus intensity at the probe does not necessarily indicate a dip in the stimulus intensity at the eardrum.

8.2.c If the stimulus level remains very low, regardless of the position of the probe in the ear, it is likely that the probe has become blocked. In this case, inspect the probe coupler tubes and replace if necessary.

Thefigurebelowisfromahealthyadultear.Thestimulus waveform panel shows a short, biphasic click stimulus. The stimulus spectrum shows a smooth distribution across the frequency range (the decrease towards 6kHz is the result ofeardrumreflection).


8.2.d A healthy newborn ear’s stimulus waveform is more oscillatory than in the adult recording. However, the oscillation is limited and the stimulus spectrum is smooth with no obvious peaks or troughs. With some newborns, a slightly roundedpeakmaybevisibleinthe2-3kHzrange.Itisadvisabletorefittheprobeuntilyouaresatisfiedthatyouhavethebestpossiblefit.

8.2.e If the stimulus level is outside the target range, this may be due to the ear canal size being outside of the range used to set the optimum stimulus level. Click on the<Auto-adjust stim> button or press A to automatically adjust the stimulus level to the target level of 84 dB pe (this default value can be changed via File > Options > Stims, if required). However, please note that it is not acceptable to compensate for a bad probefitbyincreasingthestimulus gain.

8.2.f Adjust the position of the noise rejection level slider to reject a percentage of the noisier data samples (Nhi) and improve the quality of the data accepted (Nlo). Click on the up and down arrows or use the up and down cursors to set the noise reject level. The default noise reject level can be set in the File > Options > Stims menu. If the reject level needs to be set much above 8mPa (52dB SPL), it may not be possible to record any emissions unless the subject’s OAEs are very strong. Under these circumstances, it is advisable to settle the baby, minimise cable rub and/or reassess the test environment. Intermittent sources of noise, such as background talking, may not prevent you from collecting data during the quiet periods but sources of continuous noise, such as computer hum and air-conditioning vents, will be a problem.

8.2.g Enablingthelowcutfilterwillassistinthecollectionofdatainnoisyconditions.

8.2.h Clickonthe<Continue> button to proceed to data collection.


8.3 Data collection8.3.a During data collection, TE stimuli are delivered to the ear and OAE response

data is collected. The data is averaged and an OAE waveform is displayed in the time domain. A Fast Fourier Transform is performed on the OAE response and the OAE and noise energy are displayed in a frequency spectrum. The spectrum can be displayed as a half-octave histogram, which is standard.

8.3.b As the test progresses, data is processed and various on-screen displays and figuresareupdated.TheabsoluteOAEresponse(Resp dB) relates to the total OAE energy recorded across the frequency range. The OAE response is a characteristicoftheearandtherewillbenosignificantchangethroughouttherecording. The absolute noise level recorded is also displayed, but this may reduce as the noise is averaged.

8.3.c When recording OAEs it is important that the data collected is of good quality. TheOAEsignalshouldbesignificantlylargerthanthenoisefloor,thereforeachieving a good signal-to-noise ratio (SNR). SNR values can be displayed by right-clicking the mouse on the OAE response window. In half-octave mode the OAE response histogram shows the signal and noise in half octave bands. The noise appears red in the colour display and the signal is blue. The signal-to-noise ratio in each of the bands is the difference between the signal and noise values. When a valid response exceeds the noise contamination, the signal-to-noise ratio will be positive. A dash is shown if the noise exceeds the signal. The signal to noise ratio can be improved by increasing the recording length, as the noise is averaged and reduced. Minimising the noise level in the test environment will also help. (See section OAE response window)

8.3.d During data collection, two independent collections are made using alternate pairs of stimuli. The Response Waveform panel shows these two superimposed OAE averaged waveforms (one in white and the other in yellow). The reproducibilityfigure(Repro) is derived from the correlation between the two overlaid waveforms. A perfect recording would have a reproducibility of100%.Thecorrespondingsignal-to-noiseratiowouldbeinfinitelyhigh.Anegativereproducibilityfigureindicatesthatinversionofthetwowaveformshas occurred. Noisecontaminationinthefinalresultcausesareductioninreproducibility as well as signal-to-noise ratio.

8.3.e When recording OAEs, it is important to deliver a consistent stimulus and ensure thattheprobefitremainsstable.Usingthe‘Checkfit’stimulus,theprobefitandstimulusareassessedbytheoperatorin‘Checkfit’andthetestisstartedwhenthebestpossiblefitandthedesiredstimuluslevelhavebeenachieved.Duringdata collection it is important to ensure the probe does not move considerably, thereforechangingthestimulus.Thestimulusstabilityfigure(Stab) represents anychangeinprobefitfromthestartofthetest,asapercentage.


8.3.f Alsointhestimuluswindowisastimulustrafficlightindicator.Theindicatorrepresentsthestabilityfigurewithacolourcode.Ifthestabilityfigureisover90,thenthestimulustrafficlightindicatorisgreen.Ifthestabilityisover70itisorange and if below 70 it is red.

8.4 Checkfit and testing stimuli8.4.a During CheckfitthestimulususedtoassesstheearistheOtodynamicsNon-

Linear stimulus type. From the stimuli set, positive polarity single clicks are captured.Thisstimulusresultsinasimpledeflectionoftheeardrumandfromthe measured pressure change in the ear canal, seen in the stimulus window, probefitassessmentscanbeconducted.Thisstimulustypehasbecomethestandard‘Checkfit’stimulusforOtodynamicsproductssince1988.

8.4.b During the test the stimulus changes to the selected type. When data is being collected, there are two stimuli displayed in the stimulus window. The white signal represents the stimulus at the start of the test and the green dashed signal represents the current stimulus. Any difference in the traces shows how the stimulus has changed throughout the test.

8.4.c The Otodynamics Linear stimulus type also contains some positive clicks that are the same as the Non-Linear type. These positive clicks are captured and displayed in the stimulus window. Therefore, if using the Linear or Non-Linear stimulustypesnodifferencesareseenbetweenthe‘Checkfit’stimulusandthetesting stimulus. However, if using Quickscreen, the stimulus is different. This stimulus type delivers single clicks of both positive and negative polarities and there is a slight redistribution of the stimulus energy to the 2-3Khz region from that of the other stimulus types. The stimulus waveform captured during test will thereforedifferfromthatofthe‘Checkfit’stim.

8.4.d When the test is saved the stimulus shown in the stimulus window reverts to the ‘Checkfit’stimulus.


8.4.e It is not possible to measure the stimulus accurately in noisy conditions. The stimulus stability and stimulustrafficlightindicatorsarenotupdateduntilaccurate measurements can be taken. If there are ten noisy sweeps measured in a row, the Stabilityfigureturnsredandthetrafficlightindicatorbecomescrossed hatched, indicating they are unreliable. As soon as the noise level dropstoasuitablelevelthesefiguresareupdated.

8.5 Test termination8.5.a Toterminatetherecordingmanually,pressthe<End> button. The test may also

bepausedbypressingthe<Cancel> button. This gives options to continue the test,returntothe‘Checkfit’stageorendtherecording.

8.5.b Ifdesired,theprogramcanbeconfiguredtoautomaticallystopthetestwhenspecifiedcriteriaregardingthequalityoftheOAEhavebeenmet.SeesectionTest protocols and stop logic.

8.5.c If the test is not stopped by the operator or by intervention of the stop logic, it will terminatewhenthespecifiednumberoflownoisesweepshavebeenobtained.

8.5.d If the Auto stop function is disabled, it is possible for the test length to be increased by pressing the F8 key. This will allow the test to run beyond the specifiednumberoftimeoutsweeps.(Ifyouwishtousethisfunctionduringabilateraltests,youmustensurethatthemainV6windowisactivefirst;youmaydo this by clicking on the main window). If the auto stop function is switched on, the test will terminate as programmed.

8.5.e Thefigurebelowshowsarecordingfromahealthyear.


8.5.f ThefigurebelowshowsaneonatewithalargeOAE.AhighlevelofOAEsiscommon in healthy newborn ears which are dry and clean.


8.6 OAE Response window8.6.a A right mouse click on the OAE Response window reveals various options

related to the test data. The options can be selected using a left mouse click.

8.6.b Show SNR values - This option displays the signal-to-noise ratio (SNR) values. The SNR is the difference between the OAE response and the noise level and is displayed at half octave frequencies.

8.6.c Half octave display - This groups the TEOAE response and noise energy into half octave bands and displays them in a histogram.

8.6.d Half octave display - This groups the TEOAE response and noise energy into half octave bands and displays them in a histogram.

8.6.e Examine Spectrum Detail - This opens a separate window which displays a high resolution spectrum of the OAE response. The spectrum produced is often quiteirregularandthereisnoclinicalsignificancetothedetailseen.However,changes in the detail may relate to changes in the cochlear status.

8.6.f A cursor is available and is controlled with a mouse. Place the mouse over the OAE spectrum window. Values of dBSPL and KHz, relative to the cursor movement, are displayed in the boxes at the bottom of the window. Using a left mouse click sets a reference point on the graph. Change in cursor movement fromthispointisindicatedatthebottomofthescreeninthefieldsnexttoDelta.

8.6.g It is possible to zoom in and out using a left mouse click and drag. Left to right zooms in and right to left zooms out. It is also possible to scale the graph up and down using up and down arrow keys.


8.6.h From the spectrum window, you can access a table which displays data for that test. Both the spectrum graph and the data table are printable.

8.6.i View data table - This option takes you directly to a data table, which details information about the test. Half octave data is shown.


8.7 Response Waveform window

8.7.a A right-click on the Response Waveform window reveals two further options.

8.7.b Examine waveform detail - The OAE response waveform can be examined and manipulated by using this option. During a TEOAE test, two interleaved recordings are made. These result in the responses A and B. The A and B waveforms can be combined to show the A and B mean, A and B difference or splt to show the two individal waveforms as well s the default overlaid display.

A and B waveforms overlaid Mean A and B waveforms

A and B difference A and B separated

8.7.c AnX-Ycursorisprovidedthathelpstoshowsoundpressurelevelatspecificlatencies. Clicking and holding down the left mouse button and dragging the selection box to the right will zoom in to display the selected area. The display is returned to normal by clicking and holding down the left mouse button and dragging to the left.


8.7.d Waveform Filter - ThewaveformfilterallowstheOAEresponsewaveformtobeanalysedusingafrequencyfilter.ThefeatureisusefulforanalysingspecificfrequencycomponentsofanOAEwaveforminthetimedomain.AfilteredOAE response can help determine the magnitude of certain OAE frequency componentsatspecificlatencies.Thefiltercanalsobeusedtoremoveacousticnoise from the waveform, which is often at low frequencies.

8.7.e Selectthe<Filter> button.

8.7.f Use the mouse to drag the sliders to the required frequency and then press <OK>.Thewaveformwillnowbefilteredtothefrequencylimitschosen.ThefilteredOAEwillonlycontaincomponentsbetweenthefrequencylimitsset,withtheresponseoutsidethelimitsheavilyattenuated.ThefiltercangreatlydistortOAE waveforms.

AdultOAEfilteredfrom2000Hz-3000Hz.

8.7.g Thelowerfilterrangeis50Hzto4000Hz.Theupperfilterrangeis500Hzto6000Hz.


8.7.h Remove LF noise - This feature (Remove Low Frequency Noise) will help when reviewing an OAE waveform that has been corrupted with noise. The featureappliesaseverefiltertothewaveform,attenuatingfrequenciesbelow1200 Hz and also above 4800 Hz. The probable result is a ‘cleaner’ waveform that shows a greater correlation between the A and B response, with less noise. However the OAE response will also be attenuated at these frequencies and a reduction in amplitude in the OAE waveform may be seen.

8.7.i Whenthisfilterisappliedthereproducibilityfigureisrecalculatedtoreflecttheeffectofthefilter.WhenappliedRepro isshowninitalicsandthereprofigureturnsblue.

8.8 Saving and printing the data8.8.a Oncompletingatestclickonthe<Save> button, select the correct ear from

thepop-uppromptandthenclick<OK>.Amessageconfirmsthatthedataissaved to disk. The save process stores the patient demographics and other test information in the database engine. In addition, the OAE test data is stored to diskinthestandardILOdatafileformat(compatiblewithotherOtodynamicssoftware).

8.8.b Oncethedatahasbeensaved,the<Print> button is enabled. Selecting this button will pop up a small menu which gives access to the various printing options available to TEOAE and DPOAE data.

8.8.c Note: If the ‘Print best data’ or ‘Print selected pair’ options combine TEOAE

and DPOAE tests, they will be printed on separate pages. These may be viewed on the print preview screen by using the browse buttons at the top of the screen.

8.8.1 Print this data8.8.1.a This option prints a single ear report of the data currently displayed for a

selected patient. (Fig.1 shows the print report format).

8.8.2 Print best data (both ears)8.8.2.a This option prints the ‘best’ data available for both the left and right ear tests on

the selected patient. Note: The ‘best’ data for the patient may not be the data collected in the most recent assessment. (Fig. 2 shows the print report format).


Fig1-Print this data option


Fig2-Print best data (both ears) option


8.8.3 Print selected pair8.8.3.a For a selected patient, this option allows you to choose a pair of results to print

on a report. A window opens that displays two panels and allows you to choose thedatatobeprinted.Toselectapanelusethe<Left panel>and<Right panel> buttons at the bottom of the window and the live panel is highlighted by aredlinebeneathit.Then,usingthe<Select next>and<Select previous> buttons, all the results can be scrolled through. When the desired data is displayed, press the return key or click on the print symbol to bring up the print preview. (Previewing print reports is an optional setting) The data is printed in the same orientation as chosen in the selection process.

8.8.3.b Click on the print symbol at the top of the print preview to print the data displayed. (Fig. 3 shows the print report format).

8.8.4 Print bilateral pair8.8.4.a V6 automatically detects if data is part of a bilateral pair. For a selected patient,

if the data in review is part of a simultaneous recording, then the Print bilateral pair feature becomes live. The pair of bilateral results is printed side by side on a report. (Fig. 4 shows the print report format).


Fig3-Print selected pair option


Fig4-Print bilateral pair option


8.9 Printing configuration8.9.a In the Environment section under Setup options, there are several options to

configuretheprintsetup.SelectFile > Options > Environment.

8.9.b Monochrome Prints – will print your reports in black and white.

8.9.c Preview printouts – a print preview is presented upon selection of print type.

8.9.d Inc. DP data table print – prints a data table for DP tests that includes all test pointsmeasured.(Seefig.5).

8.9.e Swap Left/Right Printing – for automated 2-tests per page printouts, the orientation of the left and right ear data is swapped.

8.9.f Print setup – displays standard windows print setup options, including printer selection.


Fig5-Data table


8.10 Formats of data stored8.10.a Data is stored on the local or a networked hard-drive, as two components, the

rawOAEdatafileandthepatientdemographicswithOAEtestsummary.

8.10.b TherawOAEdatafileisstoredinthedatafiledirectory(asspecifiedontheFile > Options > Environment settings). This contains all the waveform information foraparticulartest.AfileiscreatedforeveryOAEtestthatisperformedandsaved.EachpatientwillnormallyhaveseveralOAEdatafiles.ThesedatafilescontainmanydetailedparametersrelatedtotheindividualOAEtestmeasurement(includingOAEwaveformsetc.).Theformatofthesedatafilesisfully backward compatible with previous Otodynamics’ OAE applications.

8.10.c The patient demographics and the OAE test summary data are stored in an industry standard SQL database server. This database resides on either the same PC as the program or can be on a separate PC over a network connection.ItslocationisspecifiedintheFile > Options > Environment > Database Setup menu. This database can contain vast amounts of data with very minimal performance degradation and therefore can become a central repository for data collected from many PCs. Each data record ‘belongs’ to a user, a machine and a facility where it was created so that the data can be filteredatalaterdate.

8.10.d ThedatafilesforexporttootherdatabasemanagementsystemsaresavedinthescreeningdatatransferareadirectoryasspecifiedinFile > Options > Exports setup menu. A built-in database contains patient demographics and OAE test results etc. During the OAE test save operation and using the re-export facility it is optionally possible to save the test result to a co-operating third party screening management package. There are several pre-set options (accessed from File > Options > Exports ) which export data in the following formats. For additional information on exporting data, see the Exports and Re-export to: sections.


8.10.1 OZ8.10.1.a This option exports to the OZ SIMS patient management software. The export

filenameisOzData.bin.

8.10.2 Hi*Track8.10.2.a This option exports to the NCHAM Hi*Track software (both DOS and Windows

versions).TheexportfilenameisEZScreen.txt.

8.10.3 CSV8.10.3.a ThisoptionsexportstocommadelimitedASCIIfiles.Thisfileformatisa

common data exchange format which can be read by spreadsheet and database productssuchasMicrosoftExcel.TheexportfilenameisILOdata.csv.

8.10.4 XML8.10.4.a The XML export is similar to CSV and is an increasingly common way of moving

databetweendatabaseapplications.TheexportfilenameisEztests.xml.

8.10.5 GDT8.10.5.a This export option is available only in Germany and is for importing and

exporting data to and from GDT compliant applications.

8.10.6 ASCII8.10.6.a ThisprovidesanASCIItextfileexport.Theusercanselectdatafieldstobe

includedintheexportedfileviathe<Ascii export configure> button, which accesses the Select ascii export fields panel.


8.10.6.b The ASCII export data is written to the ILOAsciiExport.txtfile.Dataheadingsareonlywrittenonce,soiftheexportoptionsarechanged,anexistingfileshouldberenamed or deleted, otherwise any new data will not correspond to the previous headings.


9 Spontaneous OAEs (SOAEs)

9.1 What are SOAEs?9.1.a Ears with high levels of otoacoustic activity can generate sound spontaneously.

These sounds or spontaneous otoacoustic emissions (SOAEs) are typically continuously pure tones up to 30dB SPL in the sealed ear canal. Often there is more than one tone present, and there can be ten or more. The tones sometimes pulsate in intensity and sometimes alternate in frequency. The mechanism of SOAEs is believed to be the same as TEOAEs except that in the case of SOAEs the cochlea provides its own stimulus in the following way.

9.1.b Background external and physiological noise is always present in the cochlea and there is a minute transient otoacoustic emission in response to all of these sounds.WhenOAEsreachthemiddleear,somearereflectedbackintothecochlea - and become a second stimulus, which can result in a secondary OAE. These are usually smaller than the original - but in the case of SOAEs they are not.Highinternalreflectivityfromthemiddleear,combinedwithamplificationinside the cochlea, can result in the secondary emission being greater then the first.Theoriginatingsoundornoisere-circulatesinsidethecochlea.Potentiallythis sound can grow and grow - but only if one more condition is precisely met. Each re-emission must support or ‘be in phase’ with preceding emissions. Thiscanhappenatonlyspecificfrequencieswheretheroundtriptimeisexactly a whole number of wave periods. At these frequencies there can be ‘feedback’ and continuous oscillation of the cochlea. The situation is analogous to feedback howl in a public address system or a hearing aid. The internally generated signal grows quickly and stabilises at a level at which physiological activity can maintain.


9.2 How SOAEs can affect OAE measurements

9.2.a SOAEsareasignthatthecochlearamplifierisstrong-notjustattheprecisefrequency of oscillation - but over a small range of neighbouring frequencies (~1/2 octave). Strong TEOAEs are therefore also expected over this frequency range, as are strong DPOAEs. At the precise frequency of the SOAEs the TEOAEresponsecanbegreatlymagnified,resultinginasharppeakintheTEOAE spectrum and a large amplitude, oscillatory and long lasting TEOAE waveform. With DPOAEs the level may be unpredictably affected if the DPOAE frequency happens to correspond to that of an SOAE - distorting the DPgram. This is most likely at low stimulus level (less than 60dBSPL).

9.3 Detecting SOAEs9.3.a Strong SOAEs can be detected by the spectral analysis of ear canal sound,

without any stimulus being present. However, many more and weaker SOAEs can be detected by providing a small ‘synchronising’ stimulus and exploiting the power of synchronous averaging after the initial transient OAE has ended. The synchronising click interrupts the free running emissions, which then restart in a systematic way thereby assisting capture. The stimulus may also start off quasi-spontaneous emissions - which are near-spontaneous OAE oscillations which can last a second or more after stimulation but do not sustain themselves in the complete absence of stimulation.


9.4 Performing an SOAE search9.4.a ILO V6 software provides a means of searching for SOAEs using the

synchronised SOAE method. From the Test menu, select Start a Spontaneous test. The example below shows results from an ear with large SOAEs which might distort TEOAE or DPOAE responses.

9.4.b Remember - the recording of SOAEs has no direct clinical value. Approximately 50% of normal healthy young ears have some degree of SOAE activity and 50% have none. The purpose of performing an SOAE search is to determine the reason for very peaky TEOAE or DPOAE results. In research SOAEs have been used to detect minute physiological changes in cochlear function.

9.4.c Note: Stimulus stability is not recorded during SOAE tests, so the stimulus

stability displayed on screen will always read 100%.


10 Performing a DPOAE test

10.0.a ConnectaDPOAEprobeandifitisbeingusedforthefirsttime,followtheinstructions under Setup Options, Probes for registering the probe. Fit an appropriately sized probe tip.

10.0.b Ensure that the appropriate Mode is selected in File > Options > Start/Stop/Score. Protocol modes can also be changed from the status bar at the bottom of the main screen. Choose from Neonate screening, Neonate diagnostic, General screening and General diagnostic. Also ensure all options are correctly set prior to starting a test - see Setup Options section. When testing a neonate, double-check that Neonate Mode is shown at the bottom of the screen. If a neonate is tested while in one of the General Modes, the stimulus levelduringCheckfitwillinitiallybetoohigh.TohelpidentifywhenILO V6 is in neonatal mode, the status bar at the bottom of the page is coloured yellow.

Always set mode to Neonate when testing newborns or very young infants.

10.0.c Distortion Product OAEs are complex phenomena. The response obtained is governedbytheconditionofthecochleaandalsobythepreciseconfigurationof the stimulus.

10.1 Choice of Stimulation10.1.a Use the lower level stimulus for sensitive detection of abnormal function. Use

the higher level stimulus for recording DPOAEs which come from cochlear hair cells but do not necessarily mean that the hearing is within 30dB of normal.

10.1.b Use f2/f1 ratios near to 1.2 to obtain maximum strength of DPOAEs. The level difference between f1 and f2 is important. f1 level should not be lower than the f2 level. See Setup Options for further information.

10.1.c Eitherclickonthe<Start New Patient>buttonifthisisthefirsttesttobeperformed on this patient or select the patient from the patient database through the Review data panel if the patient has been previously tested. Input or edit the patient details as required. Further patient details can be entered by selectingthebuttonnextto<Start New Patient>.


10.1.d To begin a measurement, select the Tests menu and choose the type of test to be performed - for DPOAE screening select DP OAE.

10.1.e The test will automatically adopt the default stimulus - which can be examined or changed in File > Options > Stims, or Tests > Stimuli setup, or by pressing Ctrl+S. Full details are given in the Setup Options section of this manual.

10.1.f Fittheprobeintheearthenclickon<Start Test>tocommenceCheckfit.

10.2 Checkfit

10.2.a The CheckfitprocessforDPOAEsissimilartothatforTEOAEs.Arepeatedclick is presented by the probe to the ear canal. For further details, see Performing a TEOAE test, Checkfit.

10.2.b WithDPOAEcheckfit,acheckfitclickstimulusissuppliedatapresetlevelinorder to ‘sense’ the size of the ear canal and display the effect of adjusting theprobefit.TheclickisnotusedintheDPmeasurementprocess.Anydifference in ear canal size will be automatically adjusted for before the DPOAE measurement begins. It is therefore not essential for the click stimulus to reach itstargetlevelincheckfitandthe<Auto-adjust stim> button has been disabled accordingly.Onceyouhaveachievedthebestfitpossibleandaresatisfiedthatnoise levels are suitable to begin recording (see Performing a TEOAE test, Checkfit),press<Continue> or hit the Enter key.


10.3 Setting of stimulus tones10.3.a The next stage of the test procedure is the automated setting of the stimulus

tones. They are set to the levels selected in the stimuli setup. Immediately followingCheckfit,sustainedtonesorchirpsarepresentedtotheearinorderto accurately measure the ear canal frequency response. Individual ear canal geometries can vary greatly, so when performing DPOAE tests it is necessary to adjust and set the stimulus tones at each frequency tested.

10.3.b It is important to note that most probes measure the ear canal sound some distance from the ear drum at the probe tip. This means there is always an unavoidable and ‘unmeasured’ discrepancy between set and actual stimulation.

10.3.c In some ears, the frequency response is very undulating, due to standing waves and acoustic resonance. The equipment will detect this by the frequency specificnotchorpeakinthefrequencyresponse.Ifthenotchorpeakrequiresa large adjustment in order to deliver uniform sound, the correction factor will be withheld. A standing wave notch or peak at the probe may NOT indicate a notch at the eardrum. In general this technique provides a more uniform ear drum sound level.

10.3.d Therefore it is possible there will be discrepancies between the requested (set) dB SPL stimulus values and the sound recorded by the probe. For frequencies above 5000Hz, the target L1 and L2 levels rather than the levels recorded by the probe will be displayed when the levels recorded by the probe microphone are unreliable. An asterisk beside the stimulus level indicates that the target level and not the level recorded by the microphone is shown.

10.3.e Small deviations in stimulus level are important as they can lead to a substantial changeinDPOAEsoundlevel.Thedeviationsarequitefrequencyspecificsoperforming higher resolution measurements (i.e. more than 3 points per octave) can reveal the limited extent of such anomalies. Also, if the desired stimulus levels are not achieved during standard DP gram measurements, performing DPgrowthtestsatspecificfrequenciescanhelpascertaintherobustnessoftheDPOAE. (See Advanced DPOAE measurements).

10.3.f When recording DPOAEs for quantitative assessment, it is important to be cautiousoftheeffectsofearcanalfittingandstimulusadjustments.

10.3.g It can be useful to view the DP data table to check for the actual DP stimulus levels obtained during the recording. (See section OAE response window for DPOAEs).


10.3.h Note: The calibration method used for DP stimuli has been enhanced

in versions 6.41.27.0 and 6.41.27.32 onwards. If necessary for comparison with data recorded on earlier versions, the software can be switched to use the older calibration methods. Contact Otodynamics for full instructions.

10.4 Data collection

10.4.a During the recording of a DPgram the top right panel will show a graphic of a moving wave. It appears when the DP stimulus is being applied to the ear. The wave will typically show a modulated oscillatory pattern (see illustration) and this modulation is an indication of the acoustic interaction (beats) between the two stimulus frequencies being applied.

10.4.b The period of the waves will change corresponding to the frequencies actually being applied to the ear and the modulation related to the frequency ratio f2/f1 being applied at that time. The display is for indication only to serve as a reminder of the stimulus settings which have been selected. The amplitude of the wave shown will change with stimulus level - but does not display the true range of intensities the machine is capable of delivering. For this see the numerical readouts on the screen.


10.4.c As a recording is made, data at each pair of test frequencies is collected. At each frequency the amplitude at the 2F1-F2 DP frequency is recorded and displayed on the DP-Gram as the signal at the Frequency F2. The 2F1-F2 DP is believed to be produced mainly in the F2 region of the cochlea; the DP is most dependent on the condition of the cochlea around F2, so F2 is used as the nominal frequency. The noise level at frequencies adjacent to 2F1-F2 is averaged and displayed as the noise level at F2. The solid red represents this mean noise plus 1 standard deviation (mean+1sd), the hatched red represents the mean+2sd.

Right clicking on the data chart allows the data to be displayed as a bar chart, line chart (DP Gram) or as a histogram showing averaged response and the noise level in half-octave bands between 1kHz and 6kHz. The signal-to-noise ratio for each band can be viewed on the histogram in the same manner as in the TEOAE test.

10.4.d The manual test point selection buttons only become active when the minimum number of loops has been exceeded by the test.

10.4.e Once activated, this button enables a lower frequency point to be selected.

10.4.f Once activated, this button enables a higher frequency point to be selected.

10.4.g Whenoneofthemanualbuttonshasbeenused,the<Auto mode> button becomes active and, if selected, returns the test to the previously active automatic sweep mode.

10.4.h Under the OAE response graph, numerical data is displayed. As the test is running, the current level of DPOAE energy for the frequency band being sampled is displayed. Also, the achieved level of stimulus tone is shown in the F1andF2stimboxes,forthespecificfrequencybeingsampled.Anasteriskbeside the stimulus level indicates that the target level and not the level recorded by the microphone is shown (see section 10.3). On conclusion of the test, the total DP energy is reported and the target stimulus settings are shown.


10.5 DP Spectrum

10.5.a Pressing the ‘S’ key whilst a test is running will toggle a DP spectrum graph On and Off. A DP Spectrum is useful for observing the progress of a DPgram. Specificsourcesofnoisecanbeidentified.Whenthetesthasfinished,thewindow can be closed or minimised in the usual manner.


10.6 OAE response (SNR) display

10.6.a When making DPOAE recordings, it is possible to view the data in a signal-to-noise (SNR) display. The noise level is normalized to zero dB and the dB level is therefore displayed in dB SNR. This helps the operator to see the level of SNR achieved at various frequency points. The normalized mode can be particularly useful when recording DPOAEs at 8 pts/oct as it is not possible to displaytheSNRfiguresatthisresolution.

10.6.b To toggle the SNR display on and off, press the ‘N’ key.

10.6.c The option is ONLY available during the test.

10.7 Test termination10.7.a Toterminatetherecordingmanually,pressthe<End> button. The test may also

bepausedbypressingthe<Cancel> button. This gives options to continue the test,returntothe‘Checkfit’stageorendtherecording.

10.7.b Ifdesired,theprogramcanbeconfiguredtoautomaticallystopthetestwhenspecifiedcriteriaregardingthequalityoftheOAEhavebeenmet.SeesectionTest protocols and stop logic.


10.8 OAE Response window for DPOAEs

10.8.a A right mouse click on the OAE Response window reveals various options related to the test data. The options can be turned on and off using a left mouse click.

10.8.b Show SNR values - This option displays the signal-to-noise ratio (SNR) values. The SNR is the difference between the OAE response and the noise level and isspecifiedatthefrequenciestested.IftheareaonthegraphistoosmalltoclearlydisplaytheSNRfigures,theyareshownasasmalldot.

10.8.c DP line chart - This changes the view of the DP gram to a line graph format.


10.8.d DP bar graph - This changes the view of the DP gram to a bar graph format.

10.8.e DP ½ oct power display - This groups the DPOAE response energy into half octave band powers and displays them in a histogram. This option can ONLY be applied to data following a test and is not available during recording. The OAE response window is titled DP ½ oct power.

10.8.f Examine Spectrum Detail - This opens a separate window that shows the DP result in line graph format.

10.8.g A cursor is available and is controlled with a mouse. Place the mouse over the OAE spectrum window. Values of dBSPL and KHz, relative to the cursor movement, are displayed in the boxes at the bottom of the window. Using a left mouse click sets a reference point on the graph. Change in cursor movement from this point is indicated at the bottom of the screen next to Delta.

10.8.h It is possible to zoom in and out using a left mouse click and drag. Left to right zooms in and right to left zooms out. It is also possible to scale up and down using up and down arrow keys.

10.8.i From the spectrum window, it is possible to access a table which displays data for that test. Both the spectrum graph and the data table are printable.


10.8.j View data table - This option takes you directly to a data table, which details information about the test. Data is displayed for all the frequencies tested, including the measured stimulus levels and the DPOAE response at 2F1-F2. Alternative DPOAEs are also listed (2F2-F1, 3F1-2F2, 3F2-2F1, 4F1-3F2). An asterisk beside the stimulus level indicates that the target level and not the level recorded by the microphone is shown (see section 10.3).

10.9 Saving and printing the data10.9.a This data can now be saved and printed. (See Performing a TEOAE test,

Saving data and Printing data).


11 Advanced DPOAE measurements

11.1 Changing stimulus parameters for DPOAEs

11.1.a ILO V6 software allows for the programming of stimulus frequencies f1 and f2 and their levels L1 and L2. The ratio f2/f1 is set by default to 1.2:1. The levelandfrequencyoff2largelydeterminestheaudiologicalsignificanceofthe response. DPgrams with L2 of 70dBSPL are less sensitive to threshold elevation than TEOAEs. For comparable sensitivity, L2 should be 60dBSPL or less.

11.1.b The levels of stimuli f1 and f2 , L1 and L2 respectively can be set at different levels. Equal levels of L1 and L2 provide optimum responses when levels of 70dB SPL and above are used. As L2 is lowered, L1 should also be lowered but by a much smaller amount. For DPgrams sensitive to even small abnormalities, levels of L1=65dBSPL and L2=50dBSPL are often used.

11.1.c Higher stimulus levels can be useful in that if good DPOAEs are obtained but not at low levels of stimulation - cochlear function can be said to be present even though not completely normal. (See Multiple level DPOAEs below, also Gorga MP, Neely ST, Dorn PA. Distortion product otoacoustic emissions inrelationtohearingloss.In:RobinetteRM,GlattkeT(eds).OtoacousticEmissions-ClinicalApplications(SecondEdition).NewYork:Thieme,2002;243-72.)

11.1.d Although the frequency of f2 largely determines which part of the cochlea DPOAEs relate to (and hence its relation to hearing), the frequency ratio f2/f1 contributessignificantlytothis.Frequencyratiossmallerthan1.2:1generatereduced amplitude DPOAEs. Very small ratios (e.g. 1.05:1) lead to the involvement of more sections of the basilar membrane around the DP (2f1-f2) frequency place.

11.1.e Before changing DP stimulus settings the user should be referred to the literature and select well documented stimulus settings (e.g. Boerge P, Jansen TH,J.AcoustSocAm2002;111:1810-18).


11.2 Multi-level DPOAEs11.2.a DPgrams may be obtained for multiple stimulus intensities. This has several

advantages.Unusualfeatures(peaksortroughs)canbeconfirmedasbeingeitherarobustfeatureoftheearoralternativelyasveryspecifictoparticularstimulusfrequenciesandlevelsandthereforeoflessersignificance.

11.2.b It is also known that DPgrams made with lower levels of stimulation are more sensitive to pathology than those with high stimulus levels. When DPOAEs are found at higher stimulus levels but not lower stimulus levels, the suspicion ofsignificanthearinglossisincreasedandthesuspicionofaseverelossisreduced.

11.2.c Multi-level DPOAE measurements can be made at a single frequency using the V6 DP Growth function. Select the Test menu, then start DP Growth test. Select the (f2) frequency of observation and the intensity step interval.

11.2.d Healthy ears tend to show a shallow linear growth of DP decibel level with stimulus level. Ears with threshold elevation tend to show a more steep rise. However, isolated departures for a shallow linear rise are quite common and the growth function should not be used as a diagnostic indicator. It is useful as a validator of observed DPOAEs. Artifactual (instrumentation distortion) DPOAEs appear abruptly with high level stimulation.


11.2.e Although the growth of DPOAE level has been shown to be correlated to hearing threshold (seeBoergeP,JansenTH,J.AcoustSocAm2002;111:1810-18),the prediction of actual hearing threshold for an individual from DPOAE measurements is not possible with any clinically useful accuracy.

11.3 Advanced DP Growth functions

11.3.1 Background 11.3.1.a The intensity of DPOAE grows with stimulus level but in a complex way.

The levels of frequency 1 (L1) and frequency 2 (L2) are both important and an increase in just one can cause a decrease in DPOAE. Frequency 2 (the higher stimulus frequency) determines the ‘place’ of the cochlea being tested. Frequency 1 is responsible for creating the DPOAE by interacting with frequency 2 as it passes over the ‘F1’ place. There is a ‘best level’ for L1 and it is usually above L2. The lower the intensity of L2, the more L1 needs to be raised above L2. At the higher stimulus levels (e.g. 70dBSPL) L1=L2 gives nearly the maximum DPOAE, but when for example L2 = 50dBSPL an L1 of around60dBSPLgetsthebestDPOAElevel.Thiseffectwasfirstidentifiedand studied by A.M. Brown in the 1980s. It is believed to be due to the way the cochlea travelling wave changes shape with stimulus level.

11.3.2 Interpretation of DPOAE growth rate11.3.2.a DPOAE typically grows at a rate of 1dB for each 1dB increase in stimulus

intensity – but this can vary greatly. Artefactual DPOAE (e.g. from a defective probe or equipment) tends to grow much more rapidly than this. So DPOAE growth can be used to identify artefacts. Testing a cavity is the normal way to detect such artefacts but it is good practice to perform a growth measurement also on an ear since acoustic conditions can be quite different from those of a test cavity.

11.3.2.b It has been observed that DPOAE growth rates tend to increase in steepness with threshold elevation. This also means that weak stimulation will produce little DPOAE. Research has been conducted to determine if the audiometric thresholdcanbedeterminedbyfindingthelowestlevelofstimulationforwhicha DPOAE can be recognized. Results do not support the precise prediction threshold - but there is a modest correlation between individual threshold and the lowest level stimulation which produces a DPOAE. This supports the reasonable hypothesis that an ear which produces strong DPOAEs for small stimulations is a good ear with no damage to the peripheral mechanism - neither the middle ear nor the outer hair cells in the organ of Corti - and this can form the basis of a useful test for certain diagnostic applications.


11.3.3 Choosing DPOAE growth parameters11.3.3.a As explained above, the choice of stimulus levels is important and will greatly

affect the form of the growth function for an ear. In this software the user may pre-program the individual values of L1 and L2 to be used, either by editing a table or by providing the parameters for a simple formula. The default setting is for L1 and L2 to be equal and change by equal amount. Use of the default setting is unlikely to be optimum for your purposes and Otodynamics strongly advises you to consult the literature on DP growth rate and adopt an L1, L2 formula which has been demonstrated to provide the information you require.

11.3.3.b DPOAE growth rate recording is sometimes viewed on a dB OAE vs. dB L2 display. This is most common with the L1=L2 stimulus paradigm. Formula based paradigms (L1>L2) are commonly viewed on a microPascal(uPa) vs. dB L2 display. This allows for the visualization of the F2 level which fails to produce any DPOAE.

11.3.3.c The DPOAE growth test can be performed with various step sizes. A small step size will give greater resolution of detailed features but will take longer. During the test the operator may manually control the time spent on each level so as to optimize the overall quality of the recording by spending more time on the moderate and lower levels.

11.3.3.d The V6 program will automatically draw a line through the data points of a DP growth recording performed with formula or table based L1, L2. The purpose of this is to provide a simple measure of the position and angle of the DPOAE growth function for reporting purposes.


11.3.3.e Also on the display are numerical parameters characterizing the recording - these parameters are:

DP=0@L2=xx dB SPL - the level of stimulus where it is predicted/estimated that no measurable DPOAE will be produced.

dB80 - the actual or predicted level of DPOAE generated at L2=80dBSPL.

SLOPE - the rate of growth of DPOAE from DPs in microPascals per dB increase in F2.

R – (R2)Ameasureofthequalityofthefitofthebestfitlinetothedata,i.e.howcloselythelinefitsthedatapoints..AvalueofR2 close to 0 indicates that the lineisaverypoorfittothedata.Avaluecloseto1indicatesthatthelineisaverygoodfit.AlowR2valuemeansthatinformationdependingonthefitoftheline to the data, such as DP=0 and Slope, are unreliable.

11.3.3.f EachoftheseparameterswillbespecifictotheactualvaluesofL1andL2setby the operator in the table or formula. Examples of typical values can be found in the OAE literature.

11.3.3.g dB80 relates to the strength of the OAE. SLOPE relates to the quality of the cochlea with slopes below 1 and high dB80 being commonly found in a very good cochlea. DP=0@L2= xx dBSPL can be considered as a threshold but is not equivalent to the threshold of hearing and should not be used as an alternative to audiometric threshold measurement.

11.3.3.h This data is related by the formula:

OAE uPa = SLOPE (L2-L2intercept)

and dB80=20 log (SLOPE(80-L2Intercept)/Pref)

Where Pref = 20 microPascals L2 intercept = the stimulus level at frequency 2 (f2), where the DP Growth

regression line cuts the L2 (dB SPL) axis on the OAE response graph.


11.3.4 Performing DP Growth functions using the formula or table based methods

11.3.4.a To perform DP Growth tests using the formula mode or table based L1, L2, select Tests > Start a DP Growth test from the Menu.

11.3.4.b At the bottom of the parameters window, check the box for Use formula mode.

11.3.4.c The level of L1 is now determined by the formula below:

L1 = (A * L2) + B dB SPL. A is a variable factor between 0 and 2 B is a variable value between -50 and 80 in dB SPL.

11.3.4.d Either type in the chosen parameters or use the up/down arrows provided.


11.3.4.e Click on the Advanced tab to view the levels of L1 and L2 derived from the formula. It is possible to manually edit the table to further customize L1 and L2 levels.

11.3.4.f If customised table based entry is desired, the stimulus levels set can be programmedunder1of5testparadigms.Tosaveaspecificsetofstimuluslevels,selectaparadigm,editthetableasdesiredandclick<Save paradigm>. Toloadatestparadigm,selecttheonedesiredandclick<Load paradigm>.

11.3.4.g Stimulus levels entered that are not whole numbers will be rounded to the nearest integer.

11.3.4.h The highest level of L1 or L2 available is 80 dB SPL. If the variables used in the formula result in the level of L1 to be over 80 dB SPL, the levels are automatically clipped to the maximum permissible. If values are added to the table above 80 dB SPL, these are also clipped.

11.3.4.i When the desired parameters have been set, (see Choosing DPOAE growth parametersabove)press<OK>. The test sequence will begin with the ‘Checkfit’procedureasstandard.(SeePerforming a DPOAE test for more details)Whentheprobefitissatisfactorypress<Continue> to begin the test.

11.3.4.j The DP tones will be delivered and reduced in accordance with the levels of L1 andL2stipulatedbytheformulaortable.AbestfittrendlineisdrawnwhensufficientDPOAEdatapointshavebeencollected.Thetrendlinerepresentsthefall in DPOAE response with decrease in stimulation, showing the DP growth function. A weighting factor is incorporated depending on the signal-to-noise level at each level tested.

11.3.4.k To represent the data as clearly as possible, the graph will automatically re-scale on the ‘Y’ axis - either from 0-50 microPascals or from 0-100 microPascals.

11.3.4.l Whenyouaresatisfiedwiththedatacollected,press<End> to terminate the recording.


11.3.5 Saving and printing11.3.5.a Tosavethetest,clickthe<Save> button. Select the correct ear from the pop

uppromptandclick<OK>. A message will appear to say the data has been saved to disk.

11.3.5.b Toprintthedataselectthe<Print>buttonandchoose<Print this data>.

11.3.5.c Note: Only the single page test report is suitable for DPOAE growth tests.


12 Binaural OAE measurements - introduction

12.0.a In large part, our ears operate independently. For example, you can follow quiet speech with one ear while loud noise is being played in the other. For very high intensity sound can cross over the head and mask sounds in the other ear directly - but physiologically there is very little ‘cross talk’. This means OAEs can be recorded simultaneously in left and right ears which can save time.

12.0.b Binaural hearing is very important - not only for knowing the direction of a sound,butalsoforattendingtospecificsoundsinabackgroundofnoise.Thisis called the cocktail party effect and it demonstrates that there is a powerful neural processor comparing the signals from each ear. It helps build up a three-dimensional image of our sound environment so we can attend to just the sounds we want to.

12.0.c In 1991, Collet discovered that this binaural integration has a very small effect on OAEs. Contralateral noise suppresses TEOAEs by one or two dB - not enough to alter a screening result - but enough to show that the neural circuitry was active. Other contralateral suppressors were tried, but it seems that irregular sounds are most effective. There is also an ipsilateral effect, where the neural signals generated by an ear begin to affect its OAE response.

12.0.d The study of binaural interactions with OAEs is still evolving and readers are referred to the literature for the latest facts.


13 Regular binaural measurements

13.0.a The ILO292 USB-II accommodates two probes and can record from left and right ears simultaneously.

13.0.b It is possible to perform both TEOAE and DPOAE recordings bilaterally. To beginaBilateralTestselectthe<Start Bilateral Test...> button. This will commence the test procedure that has been selected as the default test. This can be chosen via Tests>’Start Test’ default action.

13.0.c Alternatively from the Tests menu, select Bilateral tests and either Start a bilateral TE test or Start a bilateral DP test.

13.0.d Notes:1 TE tests set to Stim Type Spontaneous should not be used for

bilateral recording.

2 If bilateral results recorded in V6 are opened for viewing in EZ•Screen, the stop reasons listed may not be valid.


13.0.e For regular TEOAE or DPOAE bilateral recordings, both ears receive the sametest.Whencompleted,bothresponsesaresavedbyone<Save> operation.Duringrecordingtheprobesocketusedforeachearisidentifiedon the data collection windows. When saving bilateral recordings, a simple matrix appears which allows the operator to assign the ear to the probe used. The probe sockets are labelled on the front of the ILO 292 USB-II system, with probe socket 1 on the right and probe socket 2 on the left. Once saved, each recordingcanberecalledseparatelybuttheyareidentifiedinthedatabaseasbelonging to a simultaneously recorded pair.

13.0.f The binaural and monaural OAE responses of an ear can be compared using the Examine/Compare data panel. In particular the difference function (<-Diff> button) will reveal if the response has changed as a result of binaural stimulation. The effects of contralateral stimulation are best revealed by using Linear TEOAE recording - although this mode is not suitable for regular screening or diagnostic use.


14 Advanced binaural OAE measurements

14.0.a Research enabled ILO292 USB-II systems can perform additional tests of specialist and research interest.

14.0.b V6 software provides an automated contralateral suppression recording mode.

14.0.c TheOAErecordedfromanearcanbeinfluencedbysoundpresentedtotheopposite ear. This effect is known as contralateral suppression or the cochlea reflexanditisbelievedtobecontrolledbythenervepathwaywhichrunsfromthe inner hair cells of the cochlea via the cochlear nucleus to the outer hair cells which are responsible for OAEs.

14.1 Contralateral TE suppression test

14.1.a This mode operates by making two separate OAE recordings: one of the OAE recorded when a suppressor (masker) is presented to the opposite ear (test 1), and one recorded with no suppressor (test 2). The recording of each test is switched regularly so the effect of any slow changes in recording conditions (forexamplechangesinprobefit)canbeminimizedassuchchangeswillhaveequalinfluenceonbothofthetests.

14.1.b Differences between the two results can then be ascribed to the masker. The suppression effect is small so the OAE must be measured as accurately as possible in order to record it. Good recording conditions and longer test times (more sweeps included in each test – see Timeout(sweeps) below) will aid accurate measurement.


14.1.1 Setting contralateral suppression parameters14.1.1.a To begin a TEOAE contralateral recording from the menu system, select Tests

> Bilateral Tests > Start a contralateral TE suppression test. This opens a window which allows the masker parameters to be selected.

14.1.2 Setting masking parameters14.1.2.a Setting masker level

14.1.2.b The masker level can be set so that a consistent level is achieved in all ears (Absolute Level – dBpe SPL), or set relative to the hearing threshold of the contralateral ear (Sensation Level – dBSL).

14.1.2.c If<Set absolute level masker> is selected then the masker presented will beatafixedlevelforallsubjects.

14.1.2.d Set the level required in the Masker Level (dB peSPL) box.

14.1.2.e If<Set sensation level masker> is selected then masker presented will be relative to the hearing threshold of the subject.

14.1.2.f Set the level above threshold at which you wish to present the masker in the Masker level (dB) box.


14.1.2.g With either setting method care should be taken that the suppressor level is notsetsohighthatthemiddleearreflexisactivated.TriggeringthemiddleearreflexwillalsoinfluencetheOAErecorded.

14.1.2.h Beforetheteststartsyouwillberequiredtofindthehearingthresholdforyour patient. Find the subject’s threshold by adjusting the sound level with theupanddownbuttonsthenpresentingthesoundusing<Present masker now> orbypressingthespacebar.Thestandardprocedureusedtofindhearing threshold in pure tone audiometery is recommended (for example see: www.thebsa.org.uk/docs/RecPro/PTA.pdf). When threshold has been foundselect<OK>. The masker level presented will be set relative to the threshold that was found.

14.1.2.i Masker type sets the type of sound presented to the contralateral ear. Options are broadband noise, narrowband noise of 1, ½ or ¼ octave or a tone. If narrowband or tone suppressors are chosen then the (centre) frequency must also be set. Broadband (white) noise is generally more effective a suppressor than narrowband noise or a tone.

14.1.2.j Masker centre frequency sets the frequency of the sound presented to the contralateral ear within the range 500-4000Hz. If Broadband (white) is selected then the Masker Centre Frequency is greyed out as there is no need to select a frequency for broadband noise.

14.1.2.k Setting Masker switching

14.1.2.l During testing, data collection switches between the Masker On and Masker Off conditions. Use the radio buttons to select the required switching method.

14.1.2.m If Masker On/Off time (sec) is selected then data is collected in each conditionforafixedperiodoftimebeforeswitchingtotheotherconditionregardless of the number of sweeps accepted. For example, Set to 15s might mean that that 55 sweeps (NLo) are collected in 15 seconds with the


masker and then 52 sweeps are collected in 15 seconds without the masker (because the second period was noisier and more sweeps were rejected). Switchingonatimebasismeansthetimespentineachofthefinaltestresults will be equal, but the NLo count in each test may not be.

14.1.2.n If Masker On/Off time NLo count isselectedthenafixednumberofsweeps are collected in each condition before switching to the other condition regardless of the time this takes. For example, Set to 60 might mean that 60 sweeps (NLo) are collected in 18 seconds with the masker and then 60 sweeps are collected in 15 seconds without the masker (because fewer sweeps were rejected and so less time was required to reach 60 accepted sweeps). If this method is selected then the NLo count in each ofthefinaltestresultswillbeequal,butthetimeonineachtestmaybedifferent.

14.1.2.o Stimulus Level dBpe sets the stimulus presentation level in the test ear. Lower stimulus levels have been found to be more effective in demonstrating suppression.Ifthismethodisselected,theNLocountineachofthefinaltestresults will be equal, but the time on in each test may be different.

14.1.2.p Stimulus Type sets the stimulus presented to the test ear and the time window used to record the response. The options available (Quickscreen, Nonlinear, Linear and Tone Pip) are described in full in Performing a TEOAE test.

14.1.2.q The Linear TEOAE is not suitable for regular screening or diagnostic use becauseitcancontainstimulusartefacts.Stimulusartefactsarenotinfluencedby cochlear changes so will be equal in the ‘with’ and ‘without’ noise conditions. Thereforesuchartefactsshouldnotinfluencecomparisonsbetweentheseconditions and this recording mode may be more sensitive to contralateral suppression.

14.1.2.r Timeout (sweeps) sets the number of good quality low noise sweeps (NLo) which must be recorded before the test stops.


14.1.3 Performing a TEOAE contralateral measurement14.1.3.a Oncetheparametershavebeenchosen,press<OK> to begin the test

procedure. During Checkfit, both the TE stimulus and the masker will be delivered continuously.

14.1.3.b The TE stimulus delivered to the test ear (Probe 1) is displayed on the main screen and the masking stimulus delivered to the contralateral ear (Probe 2) is displayed on the smaller OAE response with masker window.

14.1.3.c Press<Continue> to start the recording.

14.1.3.d The TEOAE response in both windows is recorded from the test ear (Probe 1). The main window displays the TEOAE response without the masker and the small window displays the TEOAE response from the same ear with the masker on.

14.1.3.e Thetestcanbemanuallyterminatedbypressing<End>; otherwise it will automaticallystoponcethespecifiednumberofdatasweepshavebeencollected. The results must be saved before they can be reviewed for evidence of suppression.


14.1.4 Saving and printing the data14.1.4.a As with other Bilateral recordings, one Save operation will store both

measurements.Press<Save> and associate the left or right ear to the probe used (Probe 1 is the test ear probe, Probe 2 the Masker probe for the contralateral ear). The results are saved as a pair within the database for easy retrieval and analysis.

14.1.4.b Toprintcontralateralsuppressiondata,selectthe<Print> button. Using the<Print Bilateral pair> option is recommended. The masked and un-masked results are displayed together on a single page. The suppressed resultisidentifiedbythemaskingstimulus,whichisdetailedatthetopofthepage.Arepresentationofthemaskerwaveformcanbeseenunder‘Checkfitstimulus’.

14.1.5 Reviewing TEOAE contralateral measurements14.1.5.a After a TEOAE contralateral recording, the patient tested remains loaded

ready for the measurements to be assessed. Select the Review tab to browse all the recordings for the patient.

14.1.5.b To load a patient previously tested, again select the Review tab. The Filters at the bottom can be used to narrow the patient search and then select Browse. Select the patient required. All the results for the patient can be observed using the Browse these tests arrows.

14.1.5.c ThesuppressedresultisidentifiedbythemaskingstimulusdisplayedintheStimulus window. The masker parameters used are also displayed.The Stim level displayed on in the Numerical Data on the suppressed result refers to the Masker level, not the stimulus evoking the OAE in the test ear.


Stimulusdisplayforthe‘Suppressed’result.TheMaskerisdisplayedinsteadofthestimulusevokingtheOAE.

Stimulusdisplayfortheunsuppressedresult.ThestimulusevokingtheOAEis displayed.

14.1.5.d Note: Echoportfirmwareversion1.0.0.4orlaterisrequiredtorunthis

test. If you are running an earlier version, contact Otodynamics for information on updating.

14.1.6 Analysis of TEOAE contralateral measurements14.1.6.a The binaural and monaural OAE responses of an ear can be compared using

the Examine/Compare data panel. In particular, the difference function, (<-Diff> button) will reveal if the response has changed as a result of binaural stimulation.

14.1.6.b Select File > Examine/Compare data from the menu. Maximise the window.


14.1.6.c Data is displayed in the left panel for the chosen patient. If the data is part of apairofresultsthe<load pair> button can be used to load the simultaneous recording into the right-hand panel.

14.1.6.d Alternatively,manuallybrowsethroughtheresultsusingthe<Select next> and <Select previous> buttons. The live panel is denoted by the red highlight line. Choosethelivepanelusingthe<Left panel>and<Right panel> buttons.

14.1.6.e With a contralateral pair of results in view, observe the OAE response value (Resp) and any change in the OAE waveform. In the half octave OAE response panel, the right-hand panel half octave level is displayed as a series of asterisks on the left-hand panel. Any difference can then clearly be seen.

14.1.6.f Pressthe<Diff> button to subtract the stimulus and OAE waveform on the right panel from the stimulus and OAE waveform on the left panel. The FFT calculation is then performed on the difference waveform, showing any change in OAE level on a frequency spectrum. This can also be observed in the half octave display mode. Using the difference function will help establish if any suppression of the OAE has occurred and at what frequencies. Observe the OAE waveform generated and the OAE response panel. Also observe the difference in response, calculated in dB SPL (Resp).

14.1.6.g To analyse the waveform in greater detail, right click on the Response Waveform panel and select Examine waveform detail. Maximise the window.


14.1.6.h The OAE response difference waveform can now be examined and manipulated. During a TEOAE test, two separate interleaved recordings are made. These result in the responses A and B. The A and B waveforms can be combined to show the A and B mean, A and B difference or split to show the two individual waveforms as well as the default overlaid display. Use the buttons at the bottom of the screen.

14.1.6.i AnX-Ycursorisprovidedtoidentifysoundpressurelevelsatspecificlatencies.Clicking and holding down the left mouse button and dragging the selection box to the right will zoom in and display the selected area. The display is returned to normal by clicking and holding down the left mouse button and dragging to the left.

14.1.6.j Methods of normalising the difference response to the OAE response size have been published in the literature. Users are strongly advised to consult the literature before commencing contralateral suppression experiments.

14.1.7 Waveform Filter14.1.7.a ThewaveformfilterallowstheOAEresponseordifferencewaveformstobe

analysedusingafrequencyfilter.(SeesectionResponse waveform window in Performing a TEOAE Test for more details)


14.1.8 Printing the difference waveform14.1.8.a It is possible to print the difference waveform in the standard single page

TEOAE test report format. In Examine and compare,select<– Diff> to display the difference waveform. Close the Examine and compare window and the differencewaveformwillbedisplayedonthemainV6screen.Select<Print> and Print this data.ThedatafileisnamedTempDiffdata.dta.


15 Reviewing data

15.0.a Click on the Review data tab. Input a name or partial name and/or ID number into the Search fieldsandclickthe<Find matches> button. Any matches will be listed and you will be able to scroll through the various matches using the top set of or arrows on this panel (TIP: use the left and right cursor keys). This is also the method for selecting previous patients when performing re-tests.

15.0.b Belowthisisthelistofdatafilesassociatedwithwhichever patient is currently being reviewed. Again it is possible to scroll through the various tests using the lower or arrows to display and print the appropriate test results (TIP: use the page-up and page-down keys).

15.0.c The<Browse> button of the Review data panel provides you with a full list of all the patients stored in the patient database. This list can befilteredusingtheFamily name and/or ID number and/or User/Machine/Facility filters.This window can be dragged wider to show additionalfields.Select<Configure ... > to show the Notes and Date of birthfieldsinthebrowse window and to choose a Compact view.


15.0.d Patient details can be changed retrospectively. Click on the This patient panel, enter the family name and ID number and click on the button to the right of the <Start new patient> button. Patient details can now be edited and are updated in the This Patient panel. Note the family name and ID number are locked. Click onthelockbuttonnexttothefamilynamefieldandawarningmessageappearsstatingthatyoucannoweditthesefields.Thisshouldbedonewithcautionasall data can be over-written.

15.1 Examine/Compare data

15.1.a This item is available when a test result is displayed on the main screen. Initiate the feature from File > Examine/Compare data or press Ctrl+E.

15.1.b Examine/Compare data provides a method of displaying two tests for a patient, side by side on the screen. It is possible to view all the tests conducted on the selectedpatientineitherpanel.Toselectapanel,usethe<Left panel> and <Right panel> buttons at the bottom of the window. The live panel is denoted bytheredhighlightline.Usethe<Select next>and<Select previous> buttons to scroll through the tests. The arrow keys on the keyboard may be used instead of the buttons on the window. The OAE data levels on the right panel are overlaid on the left panel as a series of asterisks. For TEOAE tests the data can either be overlaid at half octave frequencies or on a high resolution spectrum and for DPOAE tests, asterisks are displayed at all frequencies tested.


15.1.c For TEOAE data, the ‘difference’ function will subtract the right panel stimulus and OAE waveform from the left panel stimulus and OAE waveform. Load dataintotheleftandrightpanelandselectthe<-Diff> button. The difference waveform is displayed and the FFT calculation is then performed, showing any change in OAE level on a frequency spectrum. This can also be observed in the half octave display mode. The feature is useful when trying to observe small changes in the OAE response, perhaps when monitoring a patient over time. The subtracted data will be displayed in the live panel, denoted by the red highlight line and will be labelled TempDiff.

15.1.d It is not possible to subtract DPOAE data.

15.1.1 Comparing bilateral measurements15.1.1.a If the patient being reviewed has undergone a bilateral measurement, the V6

softwarewillautomaticallydetectifafilebeingreviewedhasapairfromasimultaneous recording.

15.1.1.b AsabilateralresultisloadedintotheExamine/Comparewindow,the<load pair> button becomes live. If activated, the other recording from that pair will be loaded automatically into the adjacent window.

15.1.1.c A printout of the Examine/Compare data window can be obtained by using the Print icon button. For further information on analysis of data, see sections OAE response window and OAE waveform window in Performing a TEOAE test and also see the OAE Response window section in Performing a DPOAE test.


16 Setup options

16.0.a All options should be correctly set prior to running a test. Click on File > Options to display the Setup Options window. A summary of all the pages within the Setup Options window are described below. Images showing all default settings are also shown.

16.1 OAE System Setup

16.1.a ThispageoftheoptionsdialoguepermitsILOV6tobeconfiguredforusewith USB hardware or as a data manager or OAE demonstrator for training purposes.

16.1.b ThispagealsoincludesanoptiontoallowthedatafilesonthisPCtobesharedby other network connections.


16.2 Stims (including setting new DPOAE high frequency range)

16.2.a Use this page for TEOAE and DPOAE stimulus and frequency range setup. The Noise reject level is common to both DP and TE tests and sets the level of noise at which sweeps are rejected. Range is 0 to 50 mPa.

16.2.1 TEOAE measurement16.2.1.a Timeout (sweeps) are the number of accepted stimulus sets presented to the

ear before the test terminates. The range is 50 to 1000. Target stim can have a value in the range of 40 to 90dBSPL (see section 8.2.a for further details). Stim type can be set to Quickscreen, Nonlinear, Linear, Spontaneous or Tone pip. See sections 8.1 and 9.1 for a detailed description of each stim type. Note: Quickscreen records twice as many stimulus responses within each sweep as Linear or Nonlinear modes. This means that for the same number of sweeps, Quickscreen will show lower noise levels.

16.2.2 DPOAE measurement16.2.2.a The adjustment of each stimulus level or selection of the preset values can

be used to set the stimulus tones. Two preset buttons are provided for quick selection of 65dB/55dB and 70dB/70dB levels. The number of testing points per octave can be set to a value of 1, 2, 3, 4 or 8. A Timeout (mins) can be set toendtheDPOAEmeasurementafteraspecifictime.TheAuto-stopfeaturemust be checked in Setup options > Start/Stop/Score in order for the DPOAE timeout to function. End frequency sets the highest L2 frequency used for DP testing and can be set to 6, 8 or 10.5kHz.


16.2.2.b The presentation of the tones can be changed to one of three options:

16.2.2.c Cyclic up: The test starts at the lowest frequency and progresses through to the higher frequencies. When the test has completed, the minimum number of loops (Setup options > Start/Stop/Score), the manual selection buttons become active.

16.2.2.d Cyclic down: The test starts at the highest frequency and descends through to the lower frequencies. When the test has completed the minimum number of loops (Setup options > Start/Stop/Score), the manual selection buttons become active.

16.2.2.e Intelligent: The test starts and runs through the minimum number of loops and then chooses test tones where the response is lowest and attempts to improve the response by receptively testing.

16.2.2.f Note: Hardware must be present to change some of these settings.


16.3 Start/Stop/Score16.3.a Start, stop, pass and scoring criteria can be set up for each protocol. Neonate

protocols allow for the addition of Mothers name, Weight (kg), Time of birth, Status and Multiple births when entering details in the This Patient panel. ThesefieldsaregreyedoutfortheGeneralprotocols.Testprotocols,stoplogicand scoring are discussed later in this manual.

Neonate Screening Mode Neonate Diagnostic Mode

General Screening Mode General Diagnostic Mode


16.4 Environment

16.4.a The Environment panelisusedtoconfigureavarietyofsectionsofILOV6.

16.4.b ALocalAreaNetwork(LAN)datafileserverissetuphere.SeeData transfer/import functions in the Data management options section.

16.4.c Theprimaryandsecondarydatafiledirectoriescanbeset.TheprimarydirectoryisthelocationwereILOV6readsandwritesdatafiles.ThesefilesstorethenecessarydatainordertocreateanOAEprofileforapatient.Thesecondaryfileisaread-onlydirectory.Thisisusefulifanotherdatasourceisavailable that you want to review in ILO V6. For example, data that is collected in the earlier ILO-V5 software.

16.4.d In the top left-hand side are settings about the display of ILO V6 graphics, which can be activated or deactivated by checking or un-checking the box respectively:

16.4.e Show No OAE icon - this is a cross symbol that can be activated and displayed if no OAE is found.

16.4.f Half octave spectra - this is a setting for a TEOAE test. This activates a display of a half octave spectrograph for the OAE response. If unchecked a high resolution spectrograph is shown. This setting can be changed using a right mouse click on the OAE response window.

16.4.g DP line graph - This changes the view of the DP gram to a line graph format.

16.4.h DP Bar Graph – This changes the view of the DP gram to a bar graph format.


16.4.i DP ½ octave power - This setting groups the DPOAE response energy into half octave bands and displays them in a histogram. This option can only be applied to data following a test and is not available during recording. The OAE response window is titled DP ½ oct power.

16.4.j All the DP graph options settings can also be changed using a right click on the OAE response window.

16.4.k Hesitation Hints - These are prompts that appear when the mouse is hovered over a particular function button to indicate how that functions works.

16.4.l Below these features are several colours schemes that can be applied.

16.4.m V6 can be run in different languages, which can be selected in this section.

16.4.n Printing options are available here:

Monochrome print – prints a black and white report.

Preview printouts – displays a print preview on selection of the report type.

Inc. DP data table print – for DP results an additional data table will be printed.

Swap Left/Right Printing - for automated two-tests per page printouts, the orientation of the left and right ear data is swapped.

16.4.o End of test sound – If selected, sounds will be played at the end of the test - a single beep for an OAE ‘pass’ result and a double beep for all other test outcomes. Note: Test sounds are not available for bilateral tests.

16.4.p Patient ID input mask -ThisallowsconfigurationfordifferentIDnumberformats, associated with each patient record. ILO V6 then enforces the input ofIDcodestothespecifiedprogramformat.TheNHSinputmaskcanbeoverridden if necessary.

16.4.q Database setup -Thisfeatureallowstheconfigurationandsetupofthedatabase. The database can be run locally on the PC being used or can be set up to and run from a server PC on a local area network (LAN). This can be advantageous if there are several PCs running ILO V6 and you want the data to be stored in a single location.

16.4.r If you select to run the database on a server, then the server PC name must be addedandtheconnectioncanthenbeconfirmed.Thedirectorypathforthedatabase can also be set for either the local or server PC.

16.4.s Printer setup -Theprintersetupoptionscanbeconfiguredhere.Theoptionsavailable are standard Windows settings which are applicable to whatever printer is set as the default Windows printer on that PC.


16.5 Exports

16.5.a Inthissectionthedirectoriesandconfigurationsettingsforanyexportorimportfilesareset.

16.5.b It is possible to set-up V6 to export test results in different formats. Data can be saved to Hi*Track (EZScreen.txt), OZ (OzData.bin), CSV (ILOdata.csv), XML (EZtests.xml) or Ascii (ILOAsciiExport.txt) formats. See the section Formats of data stored under Performing a TEOAE test for more information. If an export typeisselectedtheappropriatefileiswrittenaftereachtestiscompletedandthetestissaved.Thatfileisthenupdatedwithnewdataaftereachsubsequentsave.

16.5.c Itisalsopossibletocreateexportfilesforvarioussetsofdatausingthe Re-Export tests feature. See Re-Export to: in the Data Management section

16.5.d Thedirectorytowhichtheexportfilesarewrittencanbeconfiguredinthistab.Itmaybeusefultoexportthefilesdirectlytofloppydiskfortransfertoanothersystem.

16.5.e TheAsciiexportconfigurationissetupinthisarea.SeeFormats of data stored for more information.

16.5.f Therearetwoadditionalusersettingsforexportfiles.Thefirstistoonlycapitalisethefirstletterofthepatientnamewhenitisexported.V6holdsallpatient names within its database in capital letters. This feature therefore allows users to export data with names in a more conventional format.

16.5.g ItispossibletowritedifferentOZexportfilesforeachuser,makingiteasytoidentifyandassociateeachfiletovariousindividuals.Ifselectedthefilenamewritten is userIDOZData.bin.


16.6 Probes

16.6.a Probe performance is critical to OAE test results. Otodynamics probes store a unique ID number and a set of calibration results so that probe performance can be monitored. Before using a new probe it should be registered with your PC and a calibration check should be run and saved. Calibration tests should be run on all probes at regular intervals (weekly is recommended).

16.6.b Before using a new or different probe for testing, probes should be read, registered and a calibrated check performed.

16.6.c There are three different ways in which the probe registration and calibration facility can be entered.

By selecting File > Options > Probes.

By pressing the small probe button on the main screen next to the Save button.

By beginning a test with an unregistered probe. V6 will prompt the user to register a new probe when a test is started.


16.6.1 Registering a probe

16.6.1.a Check that the probe is connected to the OAE system. If your equipment has two probe sockets connect your probe to the socket marked 1.

16.6.1.b Open the probe registration and calibration screen.

16.6.1.c The probe ID number will appear in the Unique ID box. If the probe was connected after the probe registration and calibration window was opened then clickonthe<Read probe ID> button.

16.6.1.d Type a name into the User assigned probe name box. The probe serial number (printed on the white sleeve on the probe cable) is frequently used.

16.6.1.h Clickthe<Register this probe> button.

16.6.1.i Run the probe calibration test as described below.

16.6.2 Probe calibration test

16.6.2.a Note: Itisimportanttoensurethefirstcalibrationcheckisaccurateasit

willbeusedforreference.So,forthefirstcalibrationcheckonaprobe repeat the test and ensure the values are within +/- 0.5dB. If theresponsehaschanged,refittheprobe,ensuretheenvironmentisquiet and repeat the test. After two repeatable results check that the values are within the absolute levels shown below. If they are, select <Save>. This records these values as a reference so that any future change in probe performance can be noted.

16.6.2.b Check that the probe is connected to the OAE system. If your equipment has two probe sockets, connect your probe to the socket marked 1 (it is not possible to run probe calibration tests in socket 2. If you are running bilateral tests you will need to remove the probe connected to socket 2 and re-connect it to socket 1 in order to run the calibration test).


16.6.2.c Removethetipfromtheprobeandplacethecavityonaflatsurface.Inserttheprobe into the test cavity at a 90 degree angle to the top of the cavity, between thescrews,asshownbelowleft.Presstheprobefirmlyintothecavityuntiltheshoulder of the probe touches the top of the cavity. When released, the probe will rise a little to its natural position and the shoulder may no longer touch the cavity. Inserting the probe at the wrong angle or with the probe head over one of the screws may result in incorrect test results.

16.6.2.d Selectthe<Run calibration test>buttoninthe<Probes> area (via File > Options > Probes or click on the blue probe symbol on the main test screen).

16.6.2.d The probe response at 1, 2 and 4kHz will be measured (for dual channel UGD probes the response will be measured for both channel A and channel B. UGS probes (used for TEOAE testing only) have just a Channel A and no Channel B. For these probes the Channel B area will be blank)

16.6.2.e Relative limit check

5.6.2.f Results will be shown in red if they are different from the saved value by more than the set tolerance limits. Default limits are +/- 2dB at 1kHz, +/- 2dB at 2kHz and +/- 3dB at 4kHz. You can set your own limits for the calibration test using the<Set limits…> button beneath the probe response data.

16.6.2.g Absolute limit check

16.6.2.h Check that the new calibration values are within the range:

1kHz = 71.0dB to 83.0dB 2kHz = 74.0dB to 86.0dB 4kHz = 71.0dB to 83.0dB 6kHz = 54.0dB to 68.0dB

16.6.2.i If no results are shown in red and all results are within the absolute limits the probe has passed the calibration check.

P O


16.6.2.j If the results fail either check, the probe coupler tubes should be inspected for debris. Replace the coupler if necessary and repeat the probe test by selecting <Run calibration test>,ensuringtheearpieceisfirmlyinsertedinthetestcavity. Contamination of the coupler tubes typically reduces the levels of the higherfrequenciesfirst.Loosecouplingtothetestcavitycanreducethelowfrequencyresponseandmayartificiallyenhancethemid-frequencyresponse.

16.6.2.k If the values of the calibration results show 36dB or lower at all frequencies then there is a problem with the test. This may be due to the probe not being connected correctly or to internal wire breakage. Check the probe connection.

16.6.2.l If the results remain outside the relative limits, but within the absolute limits listed above, this indicates there have been changes in the probe but that these changes are not large enough to invalidate testing.

16.6.2.m If calibration results at any frequency remain outside the Absolute limits the probe should not be used for testing. Please contact Otodynamics’ support department. It may be possible for the probe calibration to be adjusted if the probe is returned to Otodynamics.

16.6.2.n Statistics on the currently selected probe can be viewed on the left-hand side ofthepanel.The<View cal history> button brings up a graphical display of the saved results associated with the selected probe’s calibration checks. It is possible to print this graph if you wish.


17 Test protocols and stop logic

17.0.a If desired the test termination decision can be automated. The software will end thetestwhenspecifiedcriteriahavebeenachieved.(File > Options > Start/Stop/Score) Check the box Enable Auto stop and see below for more details.

17.0.b Furtherautomationisalsoconfigurableinthissection.TheEnable Auto Start featurewillbeginthetestiftheminimumnumberofgood‘Checkfit’sweepshas been completed and if the stimulus level is correct. The test save box will automatically appear following a test, if the Enable auto save box is checked. Also the patient can be automatically scored if the Enable Auto scoring box is checked.

17.0.c It is the responsibility of the audiologist or physician to set appropriate pass/refer criteria for the test. The previous gold standard for hearing screening - the ABR - accepted a proven wave V response of normal latency to the selected level oftheclickstimulationassufficientproofofnormalauditoryfunction.Bythesame standard, any technically valid OAE response within the speech range in response to a click stimulus could be reasonably accepted as proof of adequate cochlear function. In practice, most screening programmes set more stringent criteria than this. It is common to require OAE responses to be 3 or 6dB above the noise in two, three or more half-octave bands between 1 and 4kHz. This exceeds the stringency of the ABR test, and results in a higher refer rate. However, the widespread acceptance of multi-frequency pass criteria for OAEs


must be taken to indicate an underlying dissatisfaction with the non-frequency specificnatureofscreeningABR.Itremainstobeseenifsuchstringentmulti-frequencyOAEpasscriteriapersistandyieldtangiblebenefits.

17.0.d The Start/Stop/Score menuincludesmanyflexibleoptionsthatcanbeconfiguredtoensureaconsistentminimumqualityofOAErecording.Thesoftware will not end the recording until the criteria have been met, or the number of timeout sweeps has been reached.

17.0.e The Options are:

• Minimum signal-to-noise ratio in each half-octave band• Minimum number of bands required for a pass• Selection of bands to be mandatory• Minimum number of good quality data sweeps required• Minimum valid OAE band (the minimum OAE level required in each band)• Minimum OAE response level• Minimum number of DP loops (minimum number of completed frequency

sweeps)• Minimum waveform reproducibility

17.0.f The default number of bands for a pass is three in the screening modes and four in the diagnostic modes. It is possible to specify which bands are mandatory bands in the pass criteria. The low frequency bands are dominated by physiological and background noise, especially in newborns whose ear canal walls and skulls are very thin relative to those of an adult. Therefore, to ensure that high frequency losses are not missed, you may decide to make the 4kHz band a mandatory band. A default signal-to-noise ratio of 6dB has been used in all but the 1kHz band which is often dominated by noise. A 6dB threshold is generally employed in a number of screening programs; a threshold of 3-6dB may also be statistically valid under certain circumstances.


17.0.g For TEOAE recordings, if the stop criteria are not met, data collection will stop after the designated number of low noise sweeps has been reached (Nlo 260 isdefault).DPOAErecordingswillterminateafterthespecifiedtimeout.Theseoptions can be edited in File > Options > Stims.

17.0.h You can save different stop criteria for all four modes (Neonate Screening, NeonateDiagnostic,GeneralScreeningandGeneralDiagnostic).Thespecifiedstop criteria are mainly applicable to both TEOAE and DPOAE recordings. The minimum reproducibility is applicable to TEOAE tests only and the minimum number of DP loops for DPOAE test only. The protocol can also be changed by clicking on the left-hand mouse button on Mode on the status bar at the bottom of the main screen and selecting the relevant mode from the pop-up menu. The mode cannot be changed if a test is currently running.

17.0.i Editing and saving of the pass/refer criteria and the automation options are password protected. The software installation password is required.


18 Reporting

18.0.a Reports are accessed from the menu bar. There are the options to print all Patients tested or just those that have been referred, passed, to retest, unscoredandincomplete.TheStartandEnddatescanbespecifiedandwillaffect the number of patients shown on the list. The list can also be sorted by familyname,dateofbirth,orIDnumber.Thepatientrecordscanbefilteredbyoperator,systemorfacility.The<Refresh data> button will update the list with patients currently being tested. Various reports can be printed either directly by clickingontheprintbuttonorindirectlyvia<Preview> button. Each report can be exported into XML or CSV data formats.


18.1 Operational statistics

18.1.a This section delivers information about various operational statistics within the program. Details on the Database, the Operators and the Probes stored are accessed. Analysis of the database may help determine when a back up or archive is required. The Operator section gives an overview of the tests completed and performance of the tester. The Probe section details the probes stored and the intensity of use for each probe.


19 Data management options

19.0.a There are many built in data management facilities as shown.

19.1 Backup database...

19.1.a The backup process creates a compressed archive of the entire patients’ demographicsandresultsdatabasetoaspecifiedfilename.Thebackupcanbeinvoked from the data management menu. However, ILO V6 performs backups as an automatic process so that in normal use it would not be required for the user to explicitly perform a backup. The automatic backups are performed whenever more than 200 patients have been added since the last backup, or if one month has passed since the last backup. The automatic backups are invoked as ILO V6 starts. The actual backup process is performed from within a separate ‘program’ and can continue without interrupting normal ILO V6 operation (this backup program is visible as a tray icon on the task bar).


19.2 Archiving functions

19.2.a Archiving is the process of creating a copy of the current data in a secondary location. Once the archive is complete it is then possible to remove this data from the primary data store if it is no longer required. Furthermore, it is possible to re-import data that has been archived and removed from the primary data store if it is desirable to re-examine the data at a later date.

19.2.1 Archive data...

19.2.1.a To archive data click on Data management > Archive functions > Archive data....Selecttherequiredfiltersfromthevariousfielddrop-downmenusinordertospecifythegroupofpatientstoarchive.Clickonthe<Check number matching criteria> button to ensure the correct group has been selected. Click to check/tick the Enable database archive and/or the Enable raw data archivefieldwhichwillactivatethe<Archive the files> button. Note that the <check number matching criteria> button also has to be selected to activate the<Archive the files>button.Clickthisbuttontoarchivethefiles.The<Purge archived files>buttonisnowactivated.Clickonthistopurgeallarchivedfiles.


19.2.2 Re-import from an archive

19.2.2.a Archived data can be re-imported by selecting Data Management > Archive functions > Re-import from an archive. The archive log is displayed. Highlight thearchivefileyouwishtore-importandclickon<Import selected archive>.

19.2.3 View archive log

19.2.3.a The archive history can be viewed by selecting Data management > Archive functions > View archive log which brings up the View archive history window. This window will have a vertical scroll when there are more archives than can be shown at one time. Each item in the list shows the details of the archive that was performed on that occasion. Colour highlighting is used to indicatewhetherthatparticulararchiveddatafileisavailableforre-importbackin to the master database.


19.3 Data transfer/import functions...

19.3.1 Transfer ILOv6/EZ data to server...19.3.1.a It is possible to collect ILO V6/EZ•SCREEN data on a standalone PC (typically a

notebook computer with one of the ILO Echoport family of instruments) and then transfer this data to another ILO V6 using a LAN connection. The advantages to this mode of operation are that data can be collated on a single departmental PC, or data can be placed on a more ‘secure’ PC so that patient information is not left on a vulnerable notebook PC which resides in public areas.

19.3.1.b First,ontheILOV6server,‘datafilesharing’needstobeenabledonthefirstpageoftheoptionsdialog.Thisstartsan‘ILOdatafileservice’.

19.3.1.c The transfer is initiated from the data collection ILO V6. First ensure that there is a working LAN connection to the destination ILO V6 server. Invoke the ‘transferdatabase/datafiles’windowusingeitherthesmallbuttonatthebottomof the main screen (next to the save button), or using the Data management > Data transfer/import functions > Transfer ILOV6/EZ data to server menu selection.


19.3.1.d Thelefthandpanelcontainsasetofselectionswhichcanbeusedtofilterthedata that is transferred. For example it may be a requirement to only transfer data collected by one of the users, or for a particular window of dates. Once theseselectionshavebeenmade,selectthe<Check number matching criteria>button.Thiswillcountthenumberofpatients,testsandrawdatafilesthatwouldbetransferredusingthisselectionoffiltercriteria.

19.3.1.e NexttypethenameoftheILOV6server.Thenpressthe<Check server is ready for data> button. If the server is present and ready to receive data then the<Transfer Now!> buttonwillbeenabled.Pleasenotethatboththe<Check number matching criteria>andthe<Check server is ready for data> buttons havetobepressedbeforethe<Transfer Now!> button is enabled.

19.3.1.f Duringthetransfertheprogressofthedatabaseandtherawdatafilesisdisplayed at the top of the window.

19.3.1.g Once the transfer is complete, the data is no longer present on the local PC. The data is now safely on the ILO V6 server and can be accessed there or via an ILO V6 client which is connected to the same LAN. It is now safe to disconnect this ILO V6 from the LAN and to collect some more OAE data. If you experienceanydifficulties,pleasecheckthatthe‘Fulllocalpathtodatabasefile’hasthecorrectpathandfilename(oaedata.fb).

19.3.2 Import/Synchronize ILOV6/EZ database...

19.3.2.a Click on Data management > Import/Synchronize EZ Screen data to call up Import data from EZ Screen window. Data can be imported either locally or from a remote server. If you select This computer, select the source database, otherwise select Remote Server, select server name and full pathname of databasefile.Inbothcasesthereistheoptionofsynchronizationofdatawhichis activated by clicking on the Full 2-way synchronization of data box.


19.3.2.b Note: These functions are dependent on the database type imported or

synchronised.YoucanfindthedatabasetypeintheHelp > About area. V6 databases are either Interbase (before 6.40.26.0) or Firebird (later versions). The import function will not work for the server option unless the server version is Interbase. Do not use the synchronise option unless both databases are from the same EZ•Screen / V6 installation versions. It is possible to Import data from older software versions, but not newer versions.

19.3.3 View transfer history19.3.3.a A history of data transferred across the network is displayed when View

Transfer History is selected. The history shows: the number of patients and testsanddatafilestransferred;thedateandtimeofeachtransfer;thedatabasefiltersusedtoselectthetransferredrecords;theIDoftheuserwhoinitiatedthetransfer; and the name of the server to which the records were transferred.


19.4 Import data files...

19.4.a ItispossibletoimportsomedatafilesfromILOV5softwareintotheILOV6database for storage, review and analysis.

19.4.b Priortoimportingdatafiles,copytherequiredfilestotheV6primarydatafilefolder,usingWindowsExplorer.ThisisspecifiedinV6underFile > Options > Environment > Primary data file and the default location is C:\Program Files\Otodynamics\ILO4win\DtaFiles.

19.4.c Click on Data management > Import ILO V5 data… This will open the V6 primarydatafilefolder.Selectthefilestoimportandclick<Open>. Now the data can now be viewed in ILOV6 in the usual way.

19.4.d Note: IfILOV6isconfiguredtoexportinformationtoanalternativepatientdata

management system, an option is given prior to the import process to allowthenewdatatobeautomaticallyaddedtotheexportfile.

19.4.e Currentfiletypesthatcanbeimportedare:

TEOAE Quickscreen TEOAE Non-Linear TEOAE Tone-pip DPOAE

19.4.f Note: TheILOV5datafilesdonotcontainapatientgenderorprotocol

mode information. On import to V6, the gender default is male and the protocol mode is neonatal screening. It is possible to change the gender by editing the additional patient details.


19.5 Echocheck functions

19.5.a Echochecks can store up to 96 tests in their internal non-volatile memory. This data contains the test outcome and various conditions of the test, and can be downloaded to ILO V6 using the supplied serial lead.

19.5.1 Download and import Echocheck data...19.5.1.a This section is accessed via Echocheck functions > Download and import

Echocheck data. Connect the data download lead between the Echocheck and the serial COM port on the PC. Ensure the Echocheck is switched off, selecttheusertobeassociatedwiththedataandclickthe<Download data> button. Select the appropriate COM port to which the Echocheck is attached and press OK. The Autostart facility on the Echocheck will be activated and the data will be downloaded and then erased. See note below on earlier versions of Echochecks.

19.5.1.b The data downloaded shows the test result and all the statistics collected. It is necessary to manually enter the patient name, ID number, gender details and date of birth in order to complete the record, prior to importing the test to the ILO V6 database.


19.5.1.c Todothisenterorselectthedetailsinthefieldsatthetopofthewindow,selectthe appropriate test result and use the ‘copy to selected row’ button to add the details. The same details can be added to multiple tests and a clear button has beenprovidedtoflushthefieldsreadyfordifferentpatientinformation.

19.5.1.d Data can also be saved in Hi*Track, OZ , CSV, XML, ASCII or GDT format, provided the export option is selected prior to data transfer in File > Options > Exports/Imports. This is indicated at the bottom left of the Echocheck data download window. When all of the data has the required patient information, thetestdatacanbeimportedintoILOV6byclickingonthe<Import data> button.

19.5.1.e The data is now incorporated within the ILO V6 database and can be reviewed in the same manner as other results, via the review panel. (See the Reviewing data section). The ‘stop reason’ in the Test Data panel indicates the result of the test. There is no OAE waveform data collected with the Echocheck.

19.5.1.f Please note that versions of Echochecks earlier than March 2000 (serial numbers before EC2003000) will not have the Autostart facility. If you are not sure,clickonthe<Download data> button and if the Echocheck does not start upwithinthefirsttwoseconds,switchtheEchocheckONmanually.Ifthereis more than a ten second delay, a communication with the Echocheck… message will be displayed.

19.5.2 Continue editing downloaded Echocheck data19.5.2.a It is possible to download Echocheck data and import it into the ILO V6

database at a later stage. Select Data Management > Echocheck functions > Continue editing downloaded Echocheck data. ItispossibletofiltertheresultsusingtheEchocheckID,sothatonlydatafromaspecificEchocheckisdisplayed. (The Echocheck ID is part of the unit’s serial number displayed on its back) It is then necessary to add patient details to the results prior to the import. (See section Download and Import Echocheck data). The data can now be importedbypressingthe<Import> button.


19.5.3 View imported data details

19.5.3.a A history log is available showing all the downloaded and imported data.

19.5.3.b Itispossibletofilterthedatashownbydate,usingthestartandenddropdowncalenders. The data can also be sorted by Date of test, Family name, Operator ID and Echocheck ID. The table can be printed and a print preview feature is provided. To convert the table to a different format to view in other programs, select Export to XML or Export to CSV. If the results are shown in red it indicates that they have not been imported into the main EZ•Screen database. (To import data go to Data management > Echocheck functions > Continue editing downloaded Echocheck data...). To erase the Echocheck log, select <Purge Echocheck log>.

19.6 Database maintenance

19.6.1 Database validation...19.6.1.a This function can be accessed via Data management > Database

maintenance > Database Validation. The process will read the entire database,checkforanydataintegrityerrorsandmakeseveralattemptstofixthese if present.


19.6.2 Recovery from backup...19.6.2.a Previous backups of the database can be recovered by clicking on Data

management > Database maintenance > Recovery from backup. A message is displayed warning the user that all data since the last backup will be lost if this procedure is continued. The user is asked to enter a password before proceeding with recovery.

19.6.3 Purge training mode data...19.6.3.a If training mode data is saved to the database, it will invalidate operator

statistics. A warning is raised on the exit of ILO V6 to inform the user of the presence of training mode data. At this point an option to purge the data is raised.ThefilescanalsobeerasedviaData management > Database maintenance > Purge training mode data.

19.6.4 User/Password management

19.6.4.a The need for passwords is disabled at installation and is only activated when it is required. If password protection is not required then there is no further action necessary to be able to access all functions of both ILO V6 and EZ•Screen software.

19.6.4.b ThefirstuserwillbeassignedfulladministrativerightsasanAdvancedUser.Additional Users or Advanced Users may be added to the Operator Login list, with or without passwords.


19.6.4.c Administration of passwords and user rights is achieved via the Data Management > User Password Management menu.

19.6.4.d An Advanced User may add, change or remove passwords in this User Management screen. In the column headed “UserType” the letters “A” and “S” denote “Advanced User” and “(Standard) User” respectively.

19.6.4.e By clicking in the relevant cells, it is possible to change the Forename, the FamilyName, the Password and the UserType. It is not possible to change the UserID as this may be linked to any tests which may have been performed. The changes become effective immediately so that the next user will need to be advised of the password that will allow access.

19.6.4.f Routine changes of passwords should be undertaken at regular intervals as required by the user’s institution/hospital.

19.6.5 Configure Hi*Track Users19.6.5.a ILO V6 integrates with Ht*Track by sending patient demographics in the

Hi*Track data format prior to performing a ‘merge’ into Hi*Track. However, Hi*Trackusesaseriesofpre-defined‘picklists’forcertainfields.Oneofthesepicklistsisusedtodefinethecurrentscreenername(thepersonwhoperformed the test), and another lists the possible screening sites or hospitals. As ILO V6 also uses a list of operators/screeners and sites, it is necessary to match the two lists against each other. The menu item Data management > User/Password management > Configure Hi*Track users displays a double list for both the users and sites. On the left-hand side of the dialog are the ILO V6 lists, and the Hi*Track ones are shown on the right. For every item on the ILO V6 list it is possible to select the matching item from the Hi*Track list and then press the arrow button to ‘link’ them together. Once this is done, when ILO V6 exports data to Hi*Track the data will now contain the correct Hi*Track codes for the screener and hospital site.

19.6.6 Remove unused Users/Machines19.6.6.a This section enables the user to purge unused Users and Machines from the

ILO V6 database.


19.7 Re-Export to:19.7.a Within ILO V6’s extensive data management options it is possible to export sets

of data into other data formats for viewing using different data management systems. There are two ways of doing this:

19.7.b Select Export data to: ‘data format type’, under Setup options and Exports/Imports. See sections Setup options, Exports and Formats of data stored for more details.

19.7.c Select Re-Export to:- ‘data format type’ under Data Management. Note that thetypeofexportfileneedstobesetintheSetup Options > Exports/Imports tab.

19.7.d Whenusingthefirstmethod,ILOV6writesandupdatesanexportfileaftereachtest that is saved. The Re-export feature allows the user to export various sets offilesatanytimefromthedatabase.

19.7.e Note: Records which have been archived will not be included in the Re-

exportfile.ArchivedrecordswillautomaticallyberemovedfromtheexportfileiftheRe-exportfunctionisused.

19.7.f The ‘Export type’ and ‘Export location’ are set in the ‘Exports/Imports’ section of‘SetupOptions’.Youaregiventheflexibilitytochoosebetweenwhichdatesfilesareexportedandunderwhichoperatorthetestswereperformed.

19.7.g Afterperformingthefiltering,therelevantnumberoftestsisdisplayed.Youarenowreadytoexportthefilesbypressing<Do Export Now!>.

19.7.h Theexportfilehasnowbeenwrittentothespecifiedexportlocation.


20 Help menu

20.0.a Clicking on the Help Contents or Search for Help On ... functions will open the V6 manual.

20.1 Email Dealer or Otodynamics20.1.a Click on Help from the menu bar and select the relevant option from the drop-

down list. This facility is provided as a quick and easy way to directly email either Otodynamics technical support - [email protected] - or your local dealer.

20.2 Register a new license20..2.a Please contact Otodynamics for a new license key. This can then be typed in at

Help > Register a new license.

20.3 About20.3.a This contains information relating to the current version of the software.


21 Networking

21.1 LAN client/server installation

21.1.a TheeasiestwaytoconfigureaLAN installation is to setup the ILO V6 server installationfirst.Theprocedureforthisisidenticaltothesingledesktopinstallation discussed earlier in the manual.

21.1.b ToconfigureoneormoreclientILO V6s, run the ILOv6Setup installation from the Otodynamics CD. During the setup select the ‘Network client only installation’. When ILO V6 isrunforthefirsttimethesamedialogforinitialsetupappears. This time, in addition to the user and machine details it is important to set the server name for the ILO V6 server. When the name has been entered into the dialog there is a button that will test the connection to this server.

21.1.c Once this setup is complete the patient demographics and test result summaries are stored on the ILO V6 server. The client PC performs the test and passes all of the patient information to the server PC. Therefore the responsibility for database backup and archiving now belongs to the server. If ILO V6 is run on the server, then auto backups of the database will take place at either monthly intervals or whenever 200 patients have been added to the database (whichever is sooner). If ILO V6 is never or rarely run on the server then someone must make a point of running ILO V6 so that a database backup can occur.

21.1.d Attheendofeachtest,adatafileisalsosaved.The‘raw’datafilecontainsthe details of the test (as opposed to a summary which is stored in the patient database).Theserawdatafilesarestoredinthe‘c:\programfiles\otodynamics\ilo4win\dtafiles’folderonthelocalPCbydefault.Ifyouwishthesefilestoalso be stored on the ILO V6 server then the following two settings need to be changed:

21.1.e First, on the ILO V6 server,‘datafilesharing’needstobeenabledonthefirstpageoftheoptionsdialog.Thisstartsan‘ILOdatafileservice’.


21.1.f Secondly, on the ILO V6 clientPCthe‘datafilefolder’and‘datafileservername’ need to be set to point to the ILO V6 server. Enable the ‘Use LAN data fileserver’setting,thentypeinthenameoftheILO V6 server. Now it is possible to test this connection using the button provided. During this test if a Win9x PCisfoundthentheEZ-dtafilessharenamewillbeautoenteredinthe‘datafilefolder’,andifanNT,Win2korWinXPserverisfoundthenitwillbeauto-configuredforthe‘ILOdatafileservice’.

21.1.g NowallofthepatientdemographicsandtherawdatafileswillbestoredontheILO V6 server. This data is now accessible from the ILO V6 server, or other ILO V6 clients that are also connected to the server. A typical use for this kind ofconfigurationistohavetheOAEscreenercollectingdatausinganILO V6 client. All of the data is stored on the departmental server which has had ILO V6 installed(soastoprovidethedatabaseanddatafileservice).Theaudiologistalso has an ILO V6 client (or sits at the ILO V6 server) so that they can review the OAE tests. With this kind of deployment it is possible to have multiple ILO V6 clients collecting and storing data on the same ILO V6 server - simply repeat theclientconfigurationdescribedabove.

21.2 Independent single desktop installation that periodically transfers data to an ILO V6 ‘data bank’ via the LAN

21.2.a Thisconfigurationconsistsofacombinationofthesingledesktopinstallationand the LAN installation detailed above. The OAE screener uses a single desktop installation. They collect data and store it locally on their PC (so that this PCcontainsthepatientdemographicinformationandtherawdatafiles).Duringthis data collection phase, when the screener is performing OAE tests there is no requirement for the PC to have a network connection.

21.2.b The principle of operation is that the screener collects a series of tests on their standalone ILO V6 PC. This data is held on their PC for immediate review if required. However, periodically the data is transferred or moved via the LAN to a more secure version of ILO V6 (typically running on the departmental server). When the data has been transferred it is no longer present on the screener’s PC BUT it can be reviewed from the ILO V6 server PC or any ILO V6 clients that are connected to this server. This departmental ILO V6 server is setup as described above.

21.2.c The process of transferring the data from the screener’s ILO V6 to the departmental server is described in the section Transfer EZ-screen data to server under Data Management.


21.2.d Note: If the ILO V6serveris‘behind’afirewallthefollowingportsneedto

be allowed through for ILO V6 clients to communicate. In software prior to revision v6.38.0.0, port 3050 is required for the patient database. Port 3051 is required for revision v6.38.0.0 onwards. Also,port3049isrequiredforthe‘ILOdatafileservice’.


22 Mode of operation

TEOAE TestsParameter Description

Stimulus Idle 80µs positive broadband square wave pulse with an intensity of intensity of 84dB pe (peak equivalent) in a 1cc cavity (64dBpe in 1cc if neonate mode is set).

Adjusted 80μspositivebroadbandsquarewave.

Test 300μsbiphasicbroadbandtriangularpulse(Quickscreen) 80μsalternatingbroadbandsquarewave(Linearand

Non-Linear) 2mscosinefilteredsinewaveofselectedfrequency(Tonepip)

Waveform sample rate 20kHz - Quickscreen 25kHz – All other types

Stimulus pattern Non-Linear and Tone pip

Each sweep presents 4 stimuli for each to the two response buffers (8 stimuli in total). The stimulus presentation pattern is:

X X X Y Where: Y = -3X

Quickscreen Each sweep presents 8 stimuli for each to the two response buffers

(16 stimuli in total). The stimulus presentation pattern is: X X X X X X -Y -Y Where: Y = -3X

Linear Each sweep presents 4 stimuli for each to the two response buffers

(8 stimuli in total). The stimulus presentation pattern is: X X X X

Spontaneous Each sweep presents 1 stimulus for each to the two response buffers

(2 stimuli in total).


Response buffer averaging The responses from each stimulus in a sweep are summed and

averaged. The polarity of stimuli in all types is periodically alternated.

Averaging this stimulus pattern removes artefacts which scale linearly leaving only the OAE signal which is non linear.

These sub averages are alternately added to two separate averages. These separate averages are referred to as waveforms A and B.

Signal and noise calculation Measures of signal and noise levels are based on the correlation and

differences between waveforms A and B.

Stimulus repetition rate Quickscreen One stimulus every 13ms, approximately 80 stims per second.

Linear, Non Linear and Tone pip One stimulus every 20.48ms, approximately 49 stims per second.

Spontaneous One stimulus every 80ms, approximately 12 stims per second.

Response window Quickscreen: 2.5-12.5 ms Linear, Non-Linear: 2.5-20ms Spontaneous: 21-81.9 Tonepip<2kHz:4-20ms Tone pip > 2kHz: 3-20ms Cosinefilteredwithrise(afterstartofstimulus)andfalltimeof2ms.

Response frequency bands Half octave, centres at 1, 1.4, 2, 2.8 and 4kHz.

Response frequency range 400-6400Hz


DPOAE TestsParameter Description

Checkfit stimulus 80μspositivebroadbandsquarewavepulsewithanintensityof

84dB pe (peak equivalent) in a 1cc cavity (64dBpe in 1cc if neonate mode is set).

Sample rate 25kHz

Sample buffer 81.9ms (gives 2048 points)

FFT frequency bin 25Hz

DP Noise calculation DPnoisefromthefivespectralpointsaboveandthefivepoints

below the DP frequency. In the ‘Rapid’ noise mode, the mean of these points gives the noise level. In the ‘Standard’ noise mode the mean of these points plus two standard deviations gives the noise level.

Noise rejection calculation The noise level for noise reject is calculated from the difference

between consecutive 80ms samples.

Frequency ratio F2 = 1.22 F1

DP signal reported The distortion product 2f1-f2 is reported at the nominal

frequency f2.

Response frequency range 400-10500Hz


23 Response detection

OAE response detection is based on the Signal to Noise ratio (SNR) at each testfrequency(forDPOAEtests)oracrossaspecificfrequencyrange(forTEOAE tests). Dependent upon the statistical nature of the noise, even with theprobeinacavity,thereisafiniteprobabilitythatdataatthemeasurementfrequency appears above the noise and will be considered as a ‘signal’ (i.e. a positiveSNR).ForbothtesttypesthelargertheSNRthegreatertheconfidencethat the signal detected is not a noise artefact.

ThenumberofrequiredfrequenciesforascreeningpassinfluencestheSNRrequiredforagivenlevelofconfidence.Oncethelevelofconfidenceandnumber of frequencies is decided the necessary SNR can be computed.

By running many repeat cavity tests the occurrence rates of different SNR levelsinthesetestswereusedtogeneratetheconfidencelevelsshowninthetablesreportedbelow.Theseconfidencelevelscanthenbeusedtodeterminepositive predictive value and the negative predictive value (NPV or false pass rate) which gives an essential measure of the chances of missing an ear with a significanthearingimpairment.


Confidence levels in DPOAE tests TheSNRachieveddeterminetheconfidencethataDPOAEhasbeendetected

in a test at a single frequency. The table below shows the SNR required toachieveagivenconfidencelevel(V6reportsnoiselevelsbasedonthemean+2sd):

Confidence for single frequency points SNR required for single frequency

Confidence Rapid (mean) Standard (mean +2sd)

99% 10dB 4dB

99.9% 12dB 6dB

99.99% 16dB 10dB

Confidence for multiple frequency points ScreeningtestsacquireconfidencethatOAEsarepresentbytestingacross

multiple frequency points. As the chance of an individual point passing is independent of other test points the probability of a given number of passes amongst a number of tests points can be derived.

In addition to the selected Noise Mode and the SNR, the number of pass frequencies required and the number of frequencies tested are needed to determinetheconfidencelevelachieved.Thefourtablesbelowdetailthisdatafor the two types of noise mode and for 4 and 6 point test paradigms.

Standard (mean +2 Std) based SNR values for four test points

Minimum SNR required

Confidence 2 of 4 points 3 of 4 points 4 of 4 points

99% 2dB 0dB 0dB

99.9% 3dB 2dB 0dB

99.99% 6dB 4dB 0dB


Standard (mean +2 Std) based SNR values for six test points

Minimum SNR required

Confidence 2 of 6 pts 3 of 6 pts 4 of 6 pts 5 of 6pts 6 of 6pts

99% 2dB 0dB 0dB 0dB 0dB

99.9% 4dB 2dB 0dB 0dB 0dB

99.99% 6dB 3dB 1dB 0dB 0dB

For example, if a test protocol is selected that requires 2 bands out of 6 testedanda99.9%confidenceisdesiredthenaSNRofatleast4dBmustbespecified.

Confidence levels in TEOAE tests In the case of TEOAE measurements, data points are aggregated in to

frequency bands. Normally this banding is performed as some proportion of octaves. Because of this logarithmic banding of data there is a frequency varianceintheSNRrequiredforanygivenlevelofconfidence.Thisleadstoamore complex table for the SNR required for a single band. Furthermore, this additional complexity is factored into the multiband tables found below.

Confidence for a single ½ octave band Minimum SNR required for confidence Average of

level in a single band all bands

Confidence 1kHz 1.5kHz 2kHz 3kHz 4kHz

99% 7dB 5dB 4dB 4dB 2dB 5dB

99.9% 11dB 8dB 6dB 6dB 4dB 8dB

99.99% 14dB 9dB 7dB 8dB 7dB 11dB


Confidence for multiple ½ octave bands MostTEOAEtestcriteriatestacrossallfive½octavebands,between1-4kHz:

Minimum SNR required for confidence level

Confidence 2 of 5 bands 3 of 5 bands 4 of 5 bands 5 of 5 bands

99% 2dB 0dB 0dB 0dB

99.9% 4dB 2dB 0dB 0dB

99.99% 8dB 4dB 2dB 0dB

However, in some screening protocols the 1kHz band is not used (for example in the UK newborn hearing screening programme). The table below shows the data for this situation where only 4 bands are analysed.

Minmum SNR required for confidence level

Confidence 2 of 4 bands 3 of 4 bands 4 of 4 bands

99% 2dB 0dB 0dB

99.9% 3dB 1dB 0dB

99.99% 5dB 3dB 1dB

Note: All of the above data were derived empirically from laboratory studies

using Otodynamics equipment in the presence of noise recorded from real clinics.


Conclusions

How to use this data in relation to OAE screening? Thetestconfidencepercentageisastatisticalindicatorofhowlikelythetestwill

correctly identify an ear with no OAE in response to the selected type and level of stimulus. Typically the population under test has a low prevalence of ears with no OAE. Therefore when considering the effect of a given pass protocol on the test outcome, it is more useful to examine the false pass rate or negative predictive value, as this indicates the likelihood of a subject with no OAE erroneouslybeingidentifiedashavinganormalOAE.

False pass rate (or Negative Predictive Value NPV) Thefalsepassrateforatestdependsonboththeconfidenceintheresultsof

an individual test and the incidence of the disorder tested for. The incidence of permanent hearing loss (>40 dB HL) has been estimated:

Neonate: 1-6/1000 (0.1-0.6%)*

At aged 3: 1.07%

Aged 9-6: 2.05%**

*www.asha.org/public/hearing/Prevalence-and-Incidence-of-Hearing-Loss-in-Children/ **FortnumetalBMJ2001;323:536

The incidence rate of OAEs being falsely detected for those tested in a populationwiththestatedprevalencerates(assumingallearswithsignificanthearing loss have absent OAEs) is estimated below:

Incidence of permanent hearing loss

Confidence 0.1% 1% 2%

99% 1 in100,000 1 in 10,000 1 in 5,000

99.9% 1 in 1,000,000 1 in 100,000 1 in 50,000

99.99% 1 in 10,000,000 1 in 1,000,000 1 in 500,000


DDatabase maintenance 121Database server 56Database setup 101Database validation... 121Data collection 39,65Datafiledirectory56Data management 112,113Data transfer/import functions... 115dB80 76Debris 38Defragment and re-tune... 122Diff 90,95DP ½ octave power 70DP Bar graph 70DPgram 65DPOAEs 62DPOAE growth rate 74DPOAE measurements 17DPOAE screening 63DP ½ octave power 101DP Bar Graph 100DP Growth functions 74DP Growth test 73,77DP line chart 69DP line graph 100DPOAE stimulus and frequency range

setup 97DP Spectrum 67DP spectrum graph 67

24 Index

AABR 20Absolute limit check 105Analysis 89Archive data... 113Archive log 114Archiving 113ASCII 57Asciiexportconfigure57Auditory neuropathy 20Automatic backups 112Automatic ID 32Auto stop 42,107A and B difference 46,91A and B mean 46,91A and B waveforms 46,91

BBackup database... 112Bilateral tests 81Binaural integration 80

CCheckfit38,41,63Click 38Cochlear status 20Cocktail party effect 80ConfigureHi*TrackUsers123Contralateral noise stimulation 20Contralateral recording 84Contralateral stimulation 82Contralateral suppression parameters 84Contralateral TE suppression 83CSV 23,57,120Cyclic down 98Cyclic up 98


EEchocheck data 119Echocheck functions 119Effusion 18Environment 100Equipment system checks 28Ex=OFF 26Examine/Compare data 27,89,94Examine Spectrum Detail 44,70Examine waveform detail 46Exit 28Export 26,56Exports/Imports 102EZScreen.txt 57Eztests.xml 57

Ff2/f1 65,72F2 intercept 76Facility 21Family name 32File > Options > Stims > Timeout 109Filter 47Find matches 93Fluid 38Formats of data stored 56Frequency selectivity 9

GGDT 23,57,120General diagnostic 62General screening 62Global Site Name 21,26Glue 18Grommets 18GSN 21,26

HHalf octave bands 40,107Half octave display 44Half octave spectra 100Hesitation Hints 101Hi*Track 23,120Higher frequency point 66Histogram 40Hot-keys 27Hyperbilirubinemia 20

IID number 32ILOAsciiExport.txt 58ILOdata.csv 57ILO Operator Login 23Import/Synchronize ILOV6/EZ database...

116Importing worklists 34Import data from EZ Screen 116Import ILOv5 data... 118Installation 12Intelligent 98

LLAN installation 126License key 21,125Linear stimulus 41Load pair 90,95Lower frequency point 66


MMandatory bands 108Mandatoryfields21Masking 84Masking parameters 84Middle ear status 10Mode 26,109Multi-frequency pass criteria 107

NNCHAM 57Negative pressure 18Neonate diagnostic 62Neonate screening 62Network 56Networking 126Nhi 26,39Nlo 26,39Noise 17,39,40Noise contamination 40Noise dB 26Noise rejection 25,26,39Noisy data 48Non-Linear stimulus 41

OOAE response (SNR) display 68OAE Response window 44,69Operational statistics 111Operator ID 26Oscillation 38,59Ossicular dislocation 18Otosclerosis 18OZ 57,120OzData.bin 57OZSIMSfiles23

PPass criteria 107Passwords 23Patient demographics 56Patient ID input mask 101PCspecifications11Peak stimulus level 26,38Print 27Printer setup 101printing 48Print best data (both ears) 48Print bilateral pair 51Print selected pair 51Print setup 27Print this data 48Probe calibration test 104Probefit39Probes 103Protocols 107Purgearchivedfiles113Purge Echocheck log 121Purge training mode data... 122

RRe-import from an archive 114Recording time 26Recovery from backup... 122Registering a probe 104Rej 26Relative limit check 105Remove LF noise 48Remove unused Users/Machines 123Reports 110Repro 26Reproducibility 26,40Response 26,40Response Waveform 40,46Resp dB 26Retrocochlear function 10Review data 62,93Ringing 18,38Risk factors 32


SSave 48Scoring 99Searchfields93Selectasciiexportfields57Sensitivity 9Sensory function 10Sensory transmissive loss 18Setting DPOAE frequency range 97Setup Options 96Show No OAE 100Show SNR values 44,69Signal 40Signal-to-noise ratio 44,69,108Slope 76SNR values 44SOAEs 59,60Software installation 12Spontaneous OAEs 20Spontaneous otoacoustic emissions 59Spontaneous sound emission 9Stab 26Stability 42Start/Stop/Score 99Status 26Stim dB 26Stimulation 62Stimuli 40Stimulus 38,62,129,131Stimulus frequencies 72Stimulus gain 39Stimulus intensity 38Stimulus level 38Stimulus response 38Stimulus setup 97Stimulus spectrum 38Stimulus stability 42Stimulus tones 64Stimulustrafficlightindicators42Stimulus waveform panel 38Stop logic 107Synchronization of data 116System Checks 28

TTarget range 39Target stim 97Target stimulus level 38TEOAE contralateral measurements 88TEOAE measurements 17Test termination 42,68Test time 26Timeout (sweeps) 97Tinnitus 20Transfer ILOv6/EZ data to server... 115Tympanic perforations 18

UUser 21User/Operator ID 21User/Password management 124

VView archive log 114View data table 45,71

WWaveform Filter 47,92Waveforms 40Worklist 33,34

XXML 23,57,120

ILO V6 User Manual Issue 17 - Otodynamics Ltd manual issue 17.pdf · ILO V6 Clinical OAE Software...

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Transcript of ILO V6 User Manual Issue 17 - Otodynamics Ltd manual issue 17.pdf · ILO V6 Clinical OAE Software...