Presenter:

John Pumford, Au.D., FAAA, AUD(C)

Director of Audiology and Education

Audioscan

[Photo of

Presenter]

MODERN HEARING AID VERIFICATION:

TOOLS AND TECHNIQUES FOR DELIVERING

IMPROVED PATIENT OUTCOMES

LEARNING OBJECTIVES

Use real-ear measurements (REM) more confidently in a

greater number of fitting conditions

Interpret verification findings with greater understanding

and accuracy

Solve a larger number of hearing aid fitting and

verification challenges more effectively

WHY VERIFY?

Benefits of Real-Ear Measurement

REM HAS BEEN ASSOCIATED WITH…

Improved audibility

Improved listening outcomes

Improved fitting efficiency (reduce fitting visits)

Improved patient satisfaction

Improved patient loyalty

Improved perceived quality of services

“VERIFY ACOUSTIC CHARACTERISTICS

USING PROBE MICROPHONE

MEASUREMENTS.”

INTERNATIONAL HEARING SOCIETY, BEST PRACTICES RECOMMENDATION

FOR FITTING AND DISPENSING HEARING AIDS (2019)

ARE WE CONDUCTING REM?

Surveys indicate REM not routinely done

Mueller & Strouse (1995): 39% (n=134 AuDs; n=108 HIS)

Mueller (1999): 42% combined use for those with equipment

Mueller (2003): 37% (n=558 AuDs; n=49 HIS)

Mueller (2005): 34% overall use rate w/AuDs

Mueller & Picou (2010): 42% overall use rate (n =309 AuDs; n=111

HIS)

Mueller (2014): Estimated 30% overall use rate

SOME REASONS FOR NOT USING REMS…

“The fitting software will set it right, shows me what I

need”

“Can’t be used with proprietary fitting methods”

“Patients don’t like it at target”

“Too time consuming”

“Too difficult”

“Too expensive”

“Doesn’t make a difference” [to my patients or my

practice]

CAN WE RELY ON THE FITTING SOFTWARE?

NAL-NL2 REAR Results Using 5 Different

Manufacturers’ Programming Software

Sanders, J., Stoody, T., Weber, J., Mueller, H., “Manufacturers’ NAL-NL2 Fittings Fail

Real Ear Verification” Hearing Review, March 2015; 21(3): 24-32

N = 16

55dB

Fitting software showed match within 1 dB!

65dB 75dB

NAL-NL2 COMPARISON TO 5 DIFFERENT

MANUFACTURERS’ PROPRIETARY FITTINGS

N = 16

55dB 65dB 75dB

Sanders, J., Stoody, T., Weber, J., Mueller, H., “Manufacturers’ NAL-NL2 Fittings Fail

Real Ear Verification” Hearing Review, March 2015; 21(3): 24-32

TAKEAWAYS

Selecting a fitting formula in software does not

guarantee targeted performance (or audibility)

Proprietary fitting formulas tend to underamplify vs.

validated generic fitting formula

The only way to KNOW what you are delivering to the

eardrum is through verification measures

IMPORTANCE OF ‘VERIFIED’ AUDIBILITY

Leavitt R., & Flexer, C. (2012). The importance of audibility in successful amplification of hearing loss. H Review, 19(13), 20-23.

From Mueller, H.G. (2014, January). 20Q: Real-ear probe-microphone measures - 30 years of progress? AudiologyOnline,

Manufacturer’s Formula

Fitted to NAL-R

SNR

Loss

(dB)

N = 5

IMPORTANCE OF VERIFIED AUDIBILITY – REAL WORLD

Abrams et al. (2012). Initial-fit approach versus verified prescription: comparing self-perceived hearing aid benefit. Journal of

the American Academy of Audiology. 23(10), 768-778.

N = 22

15 of 22 (~70%) preferred the verified NAL fitting

TAKEAWAYS

Hearing improvement requires more than just a ‘product’

Manner in which the product is fitted can greatly influence

benefit

Verified fit to validated targets (via professional care) can

significantly improve outcomes

GETTING STARTED

Laying the groundwork for REM

PROBE TUBE PLACEMENT CONSIDERATIONS

Location near the eardrum required

for accuracy (~5mm)

Minimizes contamination of ‘standing

waves’

Challenging

Too deep = patient discomfort

Too shallow = measurement error

12mm

12mm

5mm

5mm

PROBE TUBE PLACEMENT METHODS

Visually-assisted positioning

Use anatomy of external ear to

guide positioning

Insert probe tube until marker

approaches inter-tragal notch

Check position with otoscopy

PROBE TUBE POSITIONING

TIP: can use probe module body!

28mm

28mm

PROBE TUBE PLACEMENT METHODS

Geometrical positioning

Use ridge of earmold / hearing aid

Extend 3-5 mm beyond tip of mold

AUDIOSCAN PROBE GUIDE (PG)

Uses standing waves in ear canal to

determine probe tube location &

guide placement

Developed using machine learning

modeling and a large acoustic data

set with adult ear canals

Real-time measures compared to

acoustic model to indicate when

probe tube is within 5 mm of TM

THINGS TO CONSIDER

Developed and validated with adults w/normal outer &

middle ear function

Future studies to expand modeling data and evaluate

performance with other patient populations

Does not eliminate need for best practice procedures

with probe tube placement, particularly otoscopy

TIPS FOR REAL-EAR SETUP:

PROBE MODULE POSITIONING

TIPS FOR REAL-EAR SETUP:

CABLE ADJUSTMENT

X

TIPS FOR REAL-EAR SETUP:

PROBE TUBE INSERTION

2) Use otoscopy to check the

depth of probe tube.

1) Guide tube until mark

meets intertragal notch.

TIPS FOR REAL-EAR SETUP:

PROBE TUBE INSERTION

TIPS FOR REAL-EAR SETUP:

FOAM TIP, HEARING AID INSERTION

4) Ensure a good seal (use lubricant; let foam expand)

3) Insert earpiece(foam tip, earmold, hearing

aid)

You are ready to measure the real ear response!

REM POSITIONING CONSIDERATIONS

Locate away from reflective surfaces (~1.5 m)

Seat patient 0.5 – 1m from speaker

Balances environmental influence & patient comfort

Recommended azimuth can vary by manufacturer

0˚ or 45 ˚ typically recommended

SPEECHMAP®

The Core Verification Resource

ACCESS THE SPEECHMAP SCREEN

AUDIOMETRIC DATA ENTRY

1. Choose target

formula

2. Select age

3. Choose

audiometric

transducer

AUDIOMETRIC DATA ENTRY

4. Select RECD average,

enter, or measure

5. Select RECD Coupling

6. Select monaural or

binaural fitting

7. Select tonal or non-

tonal language (NAL-

NL2)

HL AUDIOGRAM ENTRY

THE BASIC SPEECHMAP SCREEN

SPEECHMAP AS AN INITIAL

COUNSELING TOOL

THE BASIC SPEECHMAP SCREEN

VERIFYING DEVICES USING

SPEECHMAP

FITTING TEST ONE: SOFT SPEECH

36 42

FITTING TEST TWO: AVERAGE SPEECH

FITTING TEST THREE: MPO

FINAL FITTING SUMMARY

TOOLS TO EVALUATE THE

FITTING

SII TARGET RANGES

Upper & lower limits shown in Audibars

DSL Child and Adult

Lower limit Upper limit

RMS ERROR TO TARGET

RMS ERROR TO TARGET

McCreery RW, Bentler RA, Roush PA. The Characteristics of Hearing Aid Fittings in Infants and Young Children. Ear and

Hearing. 2013:34(6):10.

BINAURAL MONITOR HEADPHONES

Listen to test-box or real ear tests.

Evaluate hearing aid function binaurally—for

easy troubleshooting.

PRE-FITTING IN THE TEST

BOX

RECD APPLICATIONS

Convert test box measures of hearing aid to estimated

real-ear aided response (S-REM)

Convert audiometry (e.g., threshold and UCL) with insert

phones from dB HL to dB SPL

RECD MEASUREMENT: HOW IS IT

DONE?

Composed of 2 measurements:

1. Coupler measurement (Transducer calibration)

2. Real-ear measurement

HOW DO WE MEASURE RECD?

1. Measure coupler

response

Verifit VF-1, Axiom, RM500SL

Verifit 2

HOW DO WE MEASURE RECD?

2. Measure Real Ear

Response

IDEAL END RESULT

Est.

Eardrum

SPL

+

Hearing aid

INPUT

Hearing aid

OUTPUT

COUPLER

RECD+ MLE

SIMULATED REM IN TEST BOX

OPEN FITTINGS

Verification Considerations

WHAT IS AN “OPEN” INSTRUMENT

“Open” NOT defined by hearing aid design

Thin Tube

RIC

“Open” defined by hearing aid coupling

If coupling does not occlude ear, it is an “Open” fitting

ONE METHOD FOR DETERMINING “OPEN” FIT

Record 65dB Speech (Test 1) with only probe tube in ear

(REUR)

Repeat 65dB Speech (Test 2) with aid in ear, but muted

(REOR)

If two results are essentially the same, it is an “Open”

fitting

OCCLUSION EFFECT TESTING

OCCLUSION EFFECT TESTING

Open Dome Closed Dome Power Dome

IF AN OPEN FITTING IS PRESENT

Consideration #1: Pre-fitting in coupler

All fitting measures should be done on

the ear

Accurately modeling on-ear venting with

coupler not currently possible

IF AN OPEN FITTING IS PRESENT

Consideration #2: Sound field calibration

Hearing aid outflow from ear canal

received by reference microphone

Lowers loudspeaker signal level

Lower input = lower measured output

IF AN OPEN FITTING IS PRESENT

Consideration #2: Sound field

calibration

Use ‘stored’ equalization (Disables ref

mic)

Outflow will not impact speaker level

If you cannot disable ref mic, move it

away from ear canal

EFFECT OF EQUALIZATION APPROACH

Mueller, H.G., Ricketts, T.A., “Open Canal Fittings” Ten Take Home Tips”, Hearing Journal, v9:11, Nov. 2006

AN OPEN-FIT SPEECHMAP PROTOCOL

Place probe tube / hearing aid as usual

Select “Open” in Instrument menu

Turn OFF (or Mute) hearing aid

Click on test signal and store

‘equalization’ when prompted

Turn ON hearing aid

Conduct Speechmap per typical

Test 1 (55dB) soft speech

Test 2 (65dB) average speech

Test 3 (75dB) loud speech

Test 4 (MPO)

ADVANCED FEATURE

VERIFICATION

Directional Microphone Testing

DIRECTIONAL TESTING (TEST BOX)

Rear speakerFront speaker

DIRECTIONAL IN TEST-BOX - BTE

Rear speakerFront speaker

DIRECTIONAL IN TEST-BOX - ITE

DIRECTIONAL TESTING (REM)

Rear speaker

Equal distance

Aided ear with

probe tube positioned

DIRECTIONAL TESTING

Omni (i.e. directional off)

Thick line represents front speaker.

Thin line

represents right

or left rear

speaker.

Curve separation indicates

directional function

DIRECTIONAL TESTING

DEMO

Directional Mic Test In Test Box

ADVANCED FEATURE

VERIFICATION

Noise Reduction Testing

NOISE REDUCTION PROPERTIES

Digital algorithm recognizes “non-speech” elements of

incoming signal Analyzes incoming signal modulation

Operates independently in bands

Performance varies greatly across manufacturers

No standardization in programming terminology

NOISE REDUCTION SIGNAL OPTIONS

NOISE REDUCTION TEST RESULT

Peak RMS Reference Curve

Noise Reduction Settled Curve

Peak RMS Reference Curve

Noise Reduction Settled Curve

DEMO

Noise Reduction Test In Test Box

ADDRESSING PATIENT ISSUES

AND TROUBLESHOOTING

CASE #1

67 y.o. male

First-time hearing instrument

wearer

Mild-moderate sloping S/N

hearing loss

Complaint:

“My own voice sounds boomy,

unnatural.”

SOME THINGS TO CHECK

Occlusion, Inadequate Venting

Occlusion Effect Test

Excessive LF Amplification

Speechmap Audibility

Listening Check with Monitor

Headset

‘Speech-Live’ while patient vocalizes

CASE #2

45 y.o. female

Experienced hearing instrument

wearer

Moderate high frequency S/N

hearing loss

Complaint:

“There is a tinny quality to sound.”

SOME THINGS TO CHECK

Probe tube placement

Not deep enough, programmed more HF

gain than needed

Remove, check, reinsert

Sound field calibration

Input may be too low (concurrent cal.),

programmed more HF gain than needed

Set venting to ‘Open’ in Speechmap

Excessive HF Amplification

Speechmap Audibility

CASE #3

70 y.o. male

First-time hearing instrument

wearer

Moderate-to-severe sloping S/N

hearing loss

Complaint:

“Still having trouble in noise.”

SOME THINGS TO CHECK

Insufficient amplification

Speechmap Audibility

Directional microphone test

Check for performance changes

Noise reduction test

INTERESTED IN LEARNING

MORE?

WEBSITE RESOURCES

www.audioscan.com/library

SUMMARY

Research and professional guidelines support the value

of REM

Reviewed procedural considerations to improve

accuracy of results and conclusions

Reviewed verification tools that evaluate device

performance, address patient complaints and inform

counseling

Verification highlights clinician value in addressing

hearing healthcare needs

QUESTIONS?