AUDIOLOGY IN AUDIOLOGY IN ORL ORL

DR. BANDAR MOHAMMED DR. BANDAR MOHAMMED AL-QAHTANI, M.DAL-QAHTANI, M.D

KSMCKSMC

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Tympanic mem & Ossicular AmplificationTympanic mem & Ossicular Amplification22:1 in total 22:1 in total 1.3:1 maleus to incus (lever action) 1.3:1 maleus to incus (lever action) 17 :1 TM surface to stapes footplate17 :1 TM surface to stapes footplateproblem in transmission leads to CHL problem in transmission leads to CHL

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Anatomy of hearing organAnatomy of hearing organTHE COCHLEATHE COCHLEA

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Traveling wave & Tonotopic Traveling wave & Tonotopic organizationorganization

Traveling wave & Tonotopic Traveling wave & Tonotopic organizationorganization

High frequency at base and low frequency at apexHigh frequency at base and low frequency at apexproblem inside the cochlea transmission leads to problem inside the cochlea transmission leads to SNHL SNHL

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Auditory AssessmentAuditory Assessment Clinical vs audiometric tests Clinical vs audiometric tests Clinical :Clinical :

- finger friction- finger friction

- watch test- watch test

- speech test- speech test

- tuning fork test - tuning fork test

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Audiometric tests :Audiometric tests : subjective vs objective tests subjective vs objective tests

- pure tone audiometry - pure tone audiometry

- speech audiometry- speech audiometry

- impedance audiometry - impedance audiometry

a-tympanometrya-tympanometry

b-acoustic reflexb-acoustic reflex

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AnatomyAnatomy

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AudiometricAudiometric AssessmentAssessment

Pure Tone AudiometryPure Tone Audiometry Speech AudiometrySpeech Audiometry Acoustic Immittance (impedance test Acoustic Immittance (impedance test

)) Auditory Brainstem ResponsesAuditory Brainstem Responses ElectrocochleographyElectrocochleography Otoacoustic EmissionsOtoacoustic Emissions

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Pure Tone AudiometryPure Tone Audiometry Most common ,subjective test Most common ,subjective test Air conduction testingAir conduction testing

Frequencies Frequencies 125,250,500,1000,2000,4000,8000 HZ125,250,500,1000,2000,4000,8000 HZ

Bone conduction testingBone conduction testing

250,500,1000,2000,4000 HZ250,500,1000,2000,4000 HZ

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Pure tone audiometryPure tone audiometry

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USES USES As baseline test (pre op and post op)As baseline test (pre op and post op) To differentiate the conductive vs sensorineural To differentiate the conductive vs sensorineural

pathway pathway The degree of handicap or heaing loss and which The degree of handicap or heaing loss and which

frequencies frequencies

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CrossoverCrossover Audiometric results are only valid when the Audiometric results are only valid when the

results are actually of the test ear.results are actually of the test ear. Interaural attenuation reflects crossover.Interaural attenuation reflects crossover. Air conduction from 40-80dBAir conduction from 40-80dB Bone conductionBone conduction

even at 0dBeven at 0dB

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MaskingMasking

The audiometric technique used to eliminate The audiometric technique used to eliminate responses by the non-test ear.responses by the non-test ear.

An appropriate noise is presented to the non-An appropriate noise is presented to the non-test ear while the test ear is being tested.test ear while the test ear is being tested.

Masking level must exceed the non-test ear Masking level must exceed the non-test ear threshold, but not create crossover.threshold, but not create crossover.

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Speech AudiometrySpeech Audiometry Determines how well a person hears and Determines how well a person hears and

understands speech,subjective test.understands speech,subjective test. Spondee wordsSpondee words SRT 50% of spondeesSRT 50% of spondees SRT should be in close correlation with SRT should be in close correlation with

PTA +- 10 db of PTA.PTA +- 10 db of PTA. Discrimination score (DS) (90-100% in Discrimination score (DS) (90-100% in

normal or conductive normal or conductive DS is 60-70 in sensory hearing loss DS is 60-70 in sensory hearing loss

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DS -(DS -(normal ,CHL, COCHLEAR &RETROCOCH normal ,CHL, COCHLEAR &RETROCOCH ROLLOVER )ROLLOVER )

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USESUSES-malingerer patients-malingerer patients-for fitting Hearing Aids-for fitting Hearing Aids-for cochlear implant patients-for cochlear implant patients-to differentiate cochlear than retro-cochlear lesion-to differentiate cochlear than retro-cochlear lesion

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Acoustic ImmittanceAcoustic Immittance Impedance: resistance to acoustic Impedance: resistance to acoustic

flow,objective testflow,objective test Admittance: ease of acoustic flowAdmittance: ease of acoustic flow Tested by:Tested by:

TympanometryTympanometry Acoustic Stapedial ReflexAcoustic Stapedial Reflex

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TympanometryTympanometryby Jergerby Jerger

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A normal between 100-(-100)A normal between 100-(-100) As stiff type otosclerosis or stiff TM.As stiff type otosclerosis or stiff TM. Ad flaccid type ossicular discontinuityAd flaccid type ossicular discontinuity B flat –fluid in ME or thick TMB flat –fluid in ME or thick TM C more in negative –retracted TMC more in negative –retracted TM

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Acoustic Stapedial ReflexAcoustic Stapedial Reflex

to elicit a stapedial muscle contraction, to elicit a stapedial muscle contraction, objective test.objective test.

3 primary acoustic reflex characteristics3 primary acoustic reflex characteristics Presence or absence of the reflexPresence or absence of the reflex Reflex thresholdReflex threshold Reflex DecayReflex Decay It tests VIII,brain stem ,VIIIt tests VIII,brain stem ,VII Good for screening in infants and Good for screening in infants and

malingerermalingerer

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Acoustic Reflex DecayAcoustic Reflex Decay Measures the ability of the stapedius Measures the ability of the stapedius

muscle to maintain sustained muscle to maintain sustained contraction.contraction.

Lower frequency tone/noise for 10 Lower frequency tone/noise for 10 secondsseconds

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Facial ParalysisFacial Paralysis Absent or abnormal stapedial reflex Absent or abnormal stapedial reflex

when the recording probe is when the recording probe is ipsilateral to the side of the lesion.ipsilateral to the side of the lesion.

Can also be helpful in locating Can also be helpful in locating lesions proximal or distal to the lesions proximal or distal to the stapedial muscle.stapedial muscle.

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Eighth nerve lesionsEighth nerve lesions Absent reflexes when stimuli is Absent reflexes when stimuli is

presented to the affected ear.presented to the affected ear. Reflexes in eighth nerve lesions are Reflexes in eighth nerve lesions are

not dependent on the degree of not dependent on the degree of hearing loss.hearing loss.

Rapid reflex decayRapid reflex decay

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Auditory Brainstem Auditory Brainstem ResponsesResponses

Impulses that are generated by the Impulses that are generated by the auditory neural pathway that can be auditory neural pathway that can be recorded on the scalp.recorded on the scalp.

objective testobjective test Not affected by sleep, sedation, or Not affected by sleep, sedation, or

attention.attention.

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Bone Conduction ABRBone Conduction ABR As reliable and repeatable as air As reliable and repeatable as air

conduction ABR.conduction ABR. Particularly useful in structural Particularly useful in structural

abnormalitiesabnormalities Canal Atresia or stenosisCanal Atresia or stenosis

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ABRABR Primary goal is a clear and reliable Primary goal is a clear and reliable

Wave IWave I Wave I : distal 8Wave I : distal 8thth nerve nerve Wave II : proximal 8Wave II : proximal 8thth nerve nerve Wave III : cochlear nucleiWave III : cochlear nuclei Wave IV : SOCWave IV : SOC Wave V : Lateral LemniscusWave V : Lateral Lemniscus

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ABRABR

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Otoacoustic EmissionsOtoacoustic Emissions

Low energy sounds produced by the Low energy sounds produced by the cochlear outer hair cells,objective test.cochlear outer hair cells,objective test.

Cochlear amplification.Cochlear amplification. Spontaneous emissionsSpontaneous emissions

Not present in greater than 25dB hearing Not present in greater than 25dB hearing loss.loss.

Evoked EmissionsEvoked Emissions Transient evokedTransient evoked Distorted ProductDistorted Product

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OAE and middle ear OAE and middle ear pathologypathology

Transmission properties of the Transmission properties of the middle ear directly influence the middle ear directly influence the OAE characteristics.OAE characteristics. Otitis mediaOtitis media NewbornsNewborns Tympanic membrane perforationsTympanic membrane perforations

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ANY QUESIONS ANY QUESIONS