hearing aid center haap workshop #8 · hearing aid. –finding f1 & f2 frequency response curve...

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HAAP Workshop #8

Lessons 29 - 32

Hearing

Aid

Center

Learners will be able to:

• Demonstrate knowledge of a standard for the electroacoustic performance analysis of hearing instruments

• Evaluate a candidate’s audiological, lifestyle, and budgetary considerations in the process of recommending appropriate amplification solutions

• Defend your recommendation(s) for amplification options for each patient/client.

• Adapt your amplification recommendations in consideration of the patient’s/client's’ impairments

• Understand and respect all patients’/clients’ perceptions of the impact of their hearing loss on activities of daily living and their desire to accept an action plan for auditory rehabilitation.

• Demonstrate all proper sanitary procedures and precautions for ear impressions

• Demonstrate safety and proficiency in making ear impressions

• Evaluate ear impressions for accuracy

Objectives

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HEARING INSTRUMENT ELECTROACOUSTIC MEASUREMENTS (ANSI STANDARDS)

Lesson 29

ANSI = American National Standards InstituteASA = Acoustical Society of America

ASA’s MissionTo generate, disseminate, and promote the knowledge and practical

applications of acoustics.

ANSI’s MissionTo enhance both the global competitiveness of U.S. business and the U.S. quality of life by promoting and facilitating voluntary consensus standards

and conformity assessment systems, and safeguarding their integrity.

ANSI/ASA Hearing Aid Standards

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ANSI Standard• Working Group 48, Subcommittee S3 Bioacoustics– Volunteers– Hearing professionals

U.S. Food and Drug Administration recognizes that the ANSI standard’s test results properly label the product.

Current Standard: ANSI/ASA S3.22-2009


The ANSI S3.22 test battery measures:

• Performance of the major components– Microphones, t-coil, and

receiver

• Battery Drain

• Digital Processer

• Air Conduction Hearing Aids

They do not measure:

• Directionality

• Bone Conduction Hearing Aids


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The benefits of ANSI testing:

1. Results can be duplicated from one test facility to another.

2. Results can be applied clinically.

3. Results can be used as the manufacturing standard for quality control purposes.

*ANSI is NOT real ear verification*


To determine if hearing aids are meeting the standard they are tested in a Hearing Instrument Test Box or “HIT Box.”


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Test Chamber:• Sealed from external noise interference

• Calibrated for a controlled test signal

• Minimizes acoustic reflections

HIT Box

Couplers:• Physically joins the HI to the microphone of the test box.

• The volume (in cubic centimeters) of the coupler approximates that of an average adult ear.– Makes performance measurements related to a consistent, relevant

standard.

HIT Box

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More Couplers• When HI’s are mounted on the coupler, any vents must be

occluded to preclude acoustical performance changes arising from venting.– Vents must be sealed on the outside surface.

Hit Box

Hit Box – Test Results

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• Most Test Boxes have an auto test feature

• Before tests are run:

– HI’s have to be programmed to “test settings” before being placed in the test box

ANSI S3.22-2009 Tests

• This is the maximum output of the hearing aid

• Measured with the input level set to 90 dB SPL over a frequency range of 200 – 5000 Hz.

• Two parameters are noted:– The frequency at which the output is maximum

• Tolerance: 3 dB for OSPL90 Max

– The High Frequency Average or HFA-OSPL90• Tolerance: +/- 4 dB for HFA-OSPL90

Maximum Output Curve (OSPL90)

(Bentler, Mueller, & Rickets, 2016)

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OSPL90

• High-Frequency Average (HFA) Full-on Gain (FOG) quantifies the gain of the HI

– HFA uses 1000, 1600, & 2500 Hz

• The input sound level is set to 50 dB SPL

• Tolerance: +/- 5 dB for FOG

Full-on Gain (FOG)

(Bentler et al., 2016)

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FOG

• This is not a test, this is a way to verify the HI meets the setting for additional testing

• A reduced volume control setting that approximates typical use gain

• Input sound level set to 60 dB SPL

• HFA-OPSL90 – 17 dB = RTG

– We want to turn down volume to a "use" setting….• So that could be the setting that allows the typical input level (65) plus variation (+12) to not exceed

OSPL90;

• So if we want to find that level…then work backwards…Take OSPL90 minus 65 minus 12

– BUT• We use 60 dB input….so we subtract 17 dB from HFA OSPL90 and adjust VC to get that output with

average input at 1, 1.6, and 2.5 kHz at 60 dB SPL

Reference Test Gain (RTG)

Thibodeau, L.M., EVALUATION OF NEW HEARING AID TECHNOLOGY[HTML Document] . Retrieved from Lecture Notes Online Web site: http://www.utdallas.edu/~thib/HA2class/HA28a_blanknotes.htm

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• A gain curve run at 60 dB SPL that allows for the calculation of the frequency range of the HI

• A way to calculate the frequency limits of the hearing aid.

– Finding F1 & F2

Frequency Response Curve

1. From the response curve determine HFA

2. Subtract 20 dB3. Draw a horizontal line parallel to the x-

axis at the reduced dB level which intersects f1 and f2

1. These values (f1 & f2) represent the frequency range of the hearing aid.

Tolerances:a. 1.25f1 or 200 Hz (whichever is higher) +/-

4dBb. .8f2 or 2000 to 4000 Hz (whichever is

lower) +/- 6dB

Frequency Response Curve


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• Measured by putting a pure tone signal into the HI and analyzing the result.

• An artifact resulting from the amplification of the signal would be classified as distortion.

• Measured with three different pure tones: 500 Hz with a 70 dB input, 800 Hz with a 70 dB input, and 1600 Hz with a 60 dB input.

• THD is expressed as a percentage.• Tolerance: Spec sheet percentage + 3% is acceptable

– Lower than the spec sheet percentage is also acceptable

Total Harmonic Distortion (THD)

(Mueller & Taylor, 2011)

Bentler et al. (2016) indicate that a high harmonic distortion measurement is a good indication that the hearing aid (often the receiver) are close to failing.

THD

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• Relates to the noise made by the circuit of the HI– Noise made by the internal noise the microphones and

receivers generate.

• Measurement of the magnitude of the noise at the output of the HI and then subtracting the gain of the hearing aid.

• As a rule of thumb this measure should be less than 30 dB

• Tolerance: EIN shall not exceed the maximum value specified by the manufacturer plus 3 dB.

Equivalent Input Noise (EIN)

(Mueller & Taylor, 2011)(Bentler et al., 2016)

• Measure of battery drain using a battery pill.– Measured using a 1000 Hz input signal at 65 dB SPL.

– Single number measure, expressed in milliamps, reflects how much current is being drawn from the battery in to the hearing aid.

– Higher than expected battery drain can be indicative of a mechanical failure that has either already occurred or will soon.

• Result should not exceed 20% of the spec sheet number.

Battery Current


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Battery mAh rating/Current Drain = Battery Life in Hours

150/1.2 = 125

Battery Life in Hours/Member’s Avg. Hours per day = Approx. days Batteries will last

125/11.5 = 10.86 Days

Battery Drain Formula

10 312 13 675

mAh rating 97 150 215 620

Important factors to consider:

• MFI Aids will have higher battery drain!– Typically takes several minutes to settle to “normal” drain after the battery

door is closed.

– Have higher battery drain when direct streaming audio.

Battery Drain

KS 6.0 (Costco’s 1st MFI HI)While steaming audio from iPhone

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• Sound Pressure Level in an Inductive Telephone Simulator (SPLITS) measures the strength of a HI’s t-coil

• Tolerance: +/- 6 dB of manufacturer’s specified value.

Telecoil Measurement


Failure to set HI in correct test settingsFailure to calibrateIncorrect couplingFailure to shut the test boxFailure to plug the vents for custom aidsNot orienting the product properly in the test box

Not placing the HI microphone close enough to the reference microphone

What Can Go Wrong?


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• Shorthand that specifies the OPSL90, the HFA-FOG, and the slope of the low frequency segment of the OPSL90 curve

• Example– 133/60/06• Output = 133 dB SPL, FOG = 60, Slope of 6 dB per octave

between 500 Hz and the next high frequency peak on the OSPL90 curve

Matrix

Best practices in HI fitting and dispensing include:• Gaining practical experience with the hearing aid test box by performing

test sequences on inventory, demo, and loaner HI’s to verify they are performing to manufacturers’ specifications.

• Performing an evaluation of every new or repaired HI that arrives at the office.

• Verifying performance of HI’s to validate a service complaint.

• Periodic check-ups that include electroacoustic analysis

Practical Applications

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HEARING INSTRUMENT CANDIDACY

Lesson 30

Guest LecturerDebbie Auzas

2018 Bay Area Regional Apprentice Training

Debbie Auzas, H.I.S.

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If a member’s audiogram shows a hearing loss, are they automatically a candidate for hearing aids?

What is the member’s motivation?

Does the member want or need a hearing device?

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It’s important to discuss the hearing loss in terms of its impact on communication effectiveness‒ As hearing loss becomes worse, problems with speech distortions, omissions, and

substitutions increase without the use of amplification

The slope and configuration of the hearing loss can introduce fitting challenges

Since most hearing loss is binaural, we typically fit both ears

Binaural fittings have several advantages compared to monaural fittings

Why then might you want to fit Monaurally?

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Monaural fitting is for one ear only ‒ When is a monaural fit appropriate?

‒ When should a monaural fit be discouraged?

Head Shadow effect‒ the effect of the head in reducing

gain on the opposite side of the head (up to 15 dB in the high frequencies)

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Auditory Deprivation ‒ Unaided ear can lose speech understanding capabilities that may not be recoverable if

binaural amplification is eventually selected

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One normal ear, one unaidable ear

Microphone and transmitter are placed on unaidable ear

Receiver is placed on the normal ear

Acoustic signals detected by the microphone are transmitted to the normal ear and sent through the ear canal by way of a thin-tube open fitting

The normal ear experiences its natural hearing and also receives the signal from the opposite side

One unaidable ear, one ear with aidable hearing loss

Fully functional hearing instrument fit to the aidable ear and … microphone/transmitter is fit to the unaidable ear

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For candidates who have significant conductive hearing loss with or without sensorineural involvement

They may have atresia, external auditory canal stenosis, chronically draining ears, or another type of craniofacial anomaly or medical condition that precludes the use of a conventional air conduction hearing aid

AKA - BAHA (Bone Anchored Hearing Aid)

Single Sided Deafness

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Does the member have any challenges with manual dexterity, visual acuity, and cognitive ability?

Size and cosmetic considerations‒ Is the member willing to wear the style of hearing aid that

you recommend?

‒ BTE or RIC versus Custom device?

Occlusion or feedback concerns‒ Adequate venting may be required to address the issue of occlusion

(tiny ears ≠ Large vents)

Feedback can cause embarrassment and annoyance‒ Also, it can cause sounds to become distorted and reduce speech intelligibility and sound

quality

Software adjustments cannot eliminate feedback when its cause is due to an inappropriate style choice!

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Accessories

Demonstrating hearing aids

Overcoming objections

Counseling

Realistic expectations

Streaming accessories

TV adapter

Remote microphone

Remote control options

Telephone/cell phone options

When is it appropriate to offer accessories to the member? Why?

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When and why should you demo hearing aids?

What is the advantage of demonstrating hearing aids?

When would you choose not to demo the hearing aids?

Objections from people who are diagnosed with a hearing loss and recommended hearing aids are common ‒ Denial

‒ Anger

‒ Embarrassment / Shame

‒ Vanity

‒ Cost

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Counseling the member and family on hearing loss and hearing aids is just as important as choosing the appropriate hearing instrument, proper physical fit, and programming

Counseling is absolutely crucial for successful fitting outcomes!‒ Does the member expect to hear the same as when they were a child with normal hearing?

‒ Setting up realistic expectations in the beginning will save you and the member time and grief in the future

Proper counseling helps guide the member to accept their hearing loss diagnosis and prepare them for realistic hearing aids wearing expectations ‒ Commit to wearing the hearing aids daily

‒ Accept that hearing aids will not fully restore normal hearing

‒ Learn proper daily cleaning and care of hearing aids

‒ Attend follow-up appointments

‒ Ask questions and communicate concerns as well as successes to their Hearing Specialist

‒ Educate family members about how they can support the member during this process

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GERIATRIC AND OTHER CONSIDERATIONS

Lesson 31

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Older adults typically have characteristics, needs, and requirements that are different

from those of the younger population.

Geriatric Considerations

Challenges faced by older adults and the hearing healthcare providers who serve them include:• Pre-fitting concerns

– Lack of problem awareness and readiness for hearing aids

• Personal characteristics during fitting– Increased likelihood of cognitive and psychoacoustic auditory processing

components to the listening difficulties

• Manual dexterity compromises• Sensory difficulties beyond hearing loss (touch and vision)• Special issues in adjusting to hearing loss and hearing aids


(Kricos, 2006)

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“The hearing healthcare professional collaborates with patients/clients in the management of their

hearing. Understanding and respecting their perception of the degree of the hearing problem

and their desire to accept amplification and auditory rehabilitation are paramount to a

successful professional relationship.”


(Professional Training Workbook in Hearing Health Sciences, 2016)

• First Impressions

• Review Case History prior to meeting member

• You must gain their trust and confidence

• Engage the member– Talk with them, not at them

– Talk to them, not to the person who brought them in

• Keep questions simple and easy to understand

• Ask them how they feel about hearing help

• Discuss their needs and concerns

• Explain the testing process and assure them that you will give them instructions for each part of the test as you move through it.

• Put the member at ease – they will be very apprehensive about the hearing test

Geriatric Considerations: Pre-test

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• Be prepared to go slower than you normally do– Your audiometric exam may take longer

• Do a practice presentation– This will give your member confidence

• Be prepared to alter your presentation based on your member’s needs• It’s okay to have the member give verbal responses if having them push the

button presents issues• Keep in mind BC testing and masking may be challenging

– In some cases they may not be completed with a high confidence in the accuracy.

• Stop throughout the test and give positive feedback– This will encourage the member and help them know they are doing what they are

expected to do

Geriatric Considerations: Testing

Don’t forget your talk over mic!You can adjust the volume for

the member’s listening comfort.

When member’s complain of an inability to hear in noise with good pure-tone and speech in quiet results, it is advisable to assess word recognition in noise.

Auditory processing disorders typically result in difficulties understanding speech in noise settings.

Geriatric Considerations: Testing

(Kricos, 2006)

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• Review your findings

• Use everyday language that is easy to understand

• Discuss the importance of the pure tone and speech testing

– AI score in relation to WRS score

– Explain that the ear is impaired, but the brain is where we hear!

• Discuss your recommendation

– Monaural or Binaural

– Hearing aid Form Factor (Style)

– Not to proceed with HI’s

– Justify your recommendation

• If you are concerned with test validity it is okay to recommend a medical referral

Geriatric Considerations: Consultation

Wearing and caring for HI’s involves a number of motor tasks:• Insertion and Removal of HI’s• Manipulative tasks such as pressing buttons, replacing batteries, changing wax

guards and domes• Maintenance tasks – Wiping, Brushing, Picking…

• You need to be evaluating your member’s manual dexterity throughout the test appointment.– Dexterity of the hands and fingers and also the ability to raise the arms to the ears.

Geriatric Considerations: Recommendations

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Factors affecting the provision of HI’s to older adults:• Manual Dexterity

– Arthritis– Parkinson’s Disease– Secondary effects of strokes– Other neurological problems

• Reduced Tactile Sensation– Affects members ability to:

• Manipulate HI controls• Insert HI batteries• Position HI’s in ears

• Other Sensory Deficits– Vison– Touch

Things to keep in mind:• You need to access the dexterity of the hands

and fingers and also the ability to raise the arms to the ears.

• When any of these factors are present, consider:– Automatic directional HI’s– Automatic t-coils– Rechargeable batteries– Raised Volume Controls– Written materials with a larger font (14 point)– Custom options may be very appropriate

Geriatric Considerations: Recommendations

(Kricos, 2006)

• Set the appointment for a time of day that the member will be attentive and not likely to fatigue.

• Allow enough time, but do not exceed an hour.– Be aware of signs of fatigue and inattention.

• Explain and run REM to verify gain settings.• Allow adequate time for learning insertion and

removal.• Practice Battery insertion and removal

Geriatric Considerations: Fitting

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Informational Counseling:

• Give the most important information first!

• Use common everyday language.

• Cover the basics.

– You can expand on them at follow-up appointments.

• Elicit the member’s understanding throughout the appointment.

• Send them home with written instructions to refer to when they forget.

– Use at least a 14 point font.

• Make sure they have a follow-up appointment scheduled when the leave.

– It’s okay to bring them back sooner if they had issues.

Geriatric Considerations: Fitting

• Be patient!

• Be prepared to review.

• Be prepared to listen.

• Be prepared to counsel.

• Be prepared to be supportive.

Geriatric Considerations: Follow-up

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• The importance of post-fitting counseling and support cannot be emphasized enough.

• A collaborative problem-solving approach to helping members cope with their listening difficulties is more successful than a one-size-fits-all approach.

• Include the members support system– Family, close friends, PCP, personal staff, living facility staff, and other healthcare providers.

• Post fitting support programs can be found in many forms.– Group and individual counseling, reading materials, use of daily journals, online resources, and

auditory rehabilitation programs.

• Self-efficacy is another consideration for older member’s who have just received HI’s.– You will need to make selections that minimize problems and make the member successful with

their new HI’s

Post-fitting Counseling

• Change is Hard!• Difficulty adjusting to amplification may

require an acclimatization strategy.• Many individuals may prefer to stay with

a style and acoustics similar to what they have successively worn.

Change

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• Some individuals process cognitive information and sensory input at slower rates.

• Allow sufficient time between test stimuli for these individuals to respond.

• Informational counseling should be provided at a slower speed.

Slower Processing Rates

• Stand or sit in front of the hearing impaired person• Ensure that their attention is on the speaker• Be sure a source of light is revealing the speakers face• Speak up but do not shout• Speak slowly and clearly, and emphasize key words• Minimize background noise if possible• Maintain eye contact• Rephrase rather than repeat• Be patient• Be supportive

Communication Strategies

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EAR IMPRESSIONS

Lesson 32

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• Quality Matters!– When the earmold lab receives a poor impression they must do

one of two things:• Request a new impression• Guess at what the impression should be

• The only part of the fitting process in which injury is possible.– Proper procedures must be followed.– We must learn and consistently practice an impression protocol

that will minimize the risk to the member.

Impressions

Costco’s Ear

ImpressionCertification

• Use common terminology when describing the anatomy of the pinna.– This ensures that both you and

the earmold lab are talking about the same anatomical feature!

• It is important to capture all of the pinna anatomy to ensure hearing aid retention.

Pinna Anatomy

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There are three basic types of impression materials:

1. Two-part vinyl polysiloxane or A+B silicone

a. Equal parts of catalyst and based are mixed together

b. Hand mixing is not possible at Costco due to our Ear Impression Protocol.

a. It is discouraged generally due to the possibility of contamination and the potential for overheating the material.

2. Silicone cartridges

a. Used in impression guns

b. Equal parts of a base and catalyst forced through a mixing tip.

c. Can have lower viscosity than A+B material

3. Powder-liquid

a. Pre-measured portion of powder combined with a precise amount of liquid and mixed.

b. Does not have resistance to heat and can distort in transit to the lab.

Always check the expiration date of your impression material prior to use.

DO NOT use material that is out of date, it may not cure properly.

Impression Materials

There are two delivery systems for impressioning:

Impression Delivery Systems

Silicone Syringe Impression Gun

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Before taking an impression:

• Review the Case History for contraindications:– Allergies

– Medications

– Surgeries

• Explain the procedure to the member

• Follow Infection Control Procedures

Impressioning Procedures

Otoscopy:

• Three Times!

1. Prior to beginning the impression

2. After placing the otoblock to verify placement

3. After removing impression from ear


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Otoscopy:

• Using proper bracing perform an otoscopic examination of the ear, ear canal, and TM.


• Are all four quadrants of the TM visible?• Are there any abnormalities present in any part of the ear?• Are there any signs of surgery?• Are there contraindications for taking the impression?• Would a medical referral be prudent?

• Note the size and direction of the canal for otoblock selection and placement.

Otoblock Selection & Placement:

• A crucial part of the impressioning process in terms of member safety.

• If size or placement are incorrect there is a risk that impression material will flow past the block (blow-by) and possibly reach the TM which has the potential to cause serious damage.

• Be meticulous in your otoblock placement and always verify with your otoscope.

– Surgical ears may need to be referred out for impressioning.


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• Two Types of otoblocks:– Foam

• Easier to verify placement visually

• May be lightly lubricated– Blood Thinner use

• Vented ones offer comfort through pressure equalization

– Cotton• DO NOT LUBRICATE – Lubrication will cause cotton otoblocks to shrink


Otoblock Selection & Placement:• Select a block that is larger in diameter than the

ear canal.• It must expand against the canal wall so that it

does not easily move when the impression material is injected against it.

• Before placing in the ear canal, tug on the vent tube to ensure it is firmly attached to the otoblock.


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Otoblock Selection & Placement:• Using a proper bracing technique (B,B,R) place the

otoblock at the canal aperture and gently use the tip of your ear light to tap around the edges of the block to place it in position.

• NEVER place an otoblock by pushing in the center of the block. You run the risk of pushing through the block.

Impressioning Process



BraceNon-Tool Hand

BraceTool Hand

RollTool Into Ear Canal

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Otoblock Selection & Placement


Once the otoblock is placed in the canal aperture -

Gently tap the otoblock with your ear light in a clockwise motion (12, 3, 6, 9 o’clock) until it is placed just beyond the second bend.

12

3

6

9

Otoblock Selection & Placement:• The block should be placed just beyond the

second bend.• The block when placed should be centered in

the canal with the vent tube coming out of the center of the block.

• There should be no visible gaps around the edges of the otoblock when it is properly placed.


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• The block must also be square in the ear canal.


Otoblock Selection & Placement:• Proper block placement ensures that you have correctly captured the

canal dimension correctly.– This ensures that the manufacturer will make a product that fits correctly and in

which the sound bore is pointed directly at the TM and not into a canal wall.

• Very small or large ears may require the use of cotton otoblocks.– When using multiple blocks for large ears, they must be tied together.

• For collapsed canals ensure that the otoblock is large enough to hold the canal open.

• Surgical ears often require multiple otoblocks to adequately seal the ear canal (Think cotton).


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Otoblock Placement Otoscopy:

• Once your otoblock is placed you must verify its placement with your otoscope!– Is it just past the second bend?

– Does it completely seal the ear canal (No Gaps!)?

– Is the block square in the canal?

– Is the vent tube centered in the canal?


Impression Material Preparation & Injection:

• Non-cartridge material:– Equal parts of the base and catalyst must be measured

out.

– The base and catalyst must be mixed on a splead pad with a spatula until it is one consistent color.

– The mixed material is placed into the syringe using a cookie cutter method.


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• Non-cartridge material


Spleading Impression Material Cookie Cutter Method


• Non-cartridge material:


Bleed off approximately a ½ inch of material prior to injecting into the ear.

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• Cartridge Material• Install cartridge in gun• Install new tip on cartridge• Eject and discard

approximately ½ inch of material

Impression Material Preparation & Injection:Bracing:


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Impression Material Preparation & Injection:• Technique is similar regardless of tool.

– Place the tip of the tool approximately ½ way between the canal aperture and the otoblock.

– Slowly but firmly inject the impression material.– When the material begins to flow out of the ear and around the tip of the tool,

keeping the tip of the tool below the surface of the material begin to move out of the ear canal.

– When the canal is filled move down to fill the concha beginning at the intertragal notch and working upward.

– Make certain that both the tragus and antitragus are covered and that the entire concha is filled.

– Continue into the upper concha or helix area and into the helix curl.




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Impression Material Preparation & Injection:• Excessive pressure during material injection:

– Can cause damage to the member’s ear Blow-By– Can cause unwanted expansion of the ear canal that may cause discomfort once the

earpiece is fit.

• Jaw movement is discouraged during the curing.– Movement will distort the shape of the canal at its deepest points and can result in

acoustic feedback from the finished earpiece.

• Allow the material to cure for the time specified by the supplier.– Remember the ½ inch of bleed off?– Premature removal will result in a distorted impression at best, and at worst an

impression may separate into pieces which could remain in the canal.


Impression Removal:

• Pull up and back on the pinna

• Release the helix curl and upper concha

• Rotate the impression forward and gently pull it out of the ear

– Do not pull it so hard that it stretches or breaks


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Impression Removal:

• IMMEDIATELY upon removal of the impression set it down, without looking at it, and perform otoscopy.– Ensure that no damage has been done

to the ear canal.

– Ensure that no impression material has been left behind.


Impression Critique:

• A good impression must:

– Have a complete canal that reaches the second bend.

– A concha that is complete and shows both the tragus and antitragus.

– A well defined intertragal notch and helix curl

Impression Process

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Impression Critique:

• A bad impression:– Has voids

–Weld marks

– Does not meet the otoblock

– Is under filled

– Is overfilled

Impression Process

Void

Short

Overfilled

Under filled

Impression Process

Will it fit?

After completing your impression make a determination about the size of the ear canal in relation to the size of the receiver.

Determine if it is realistic to ask the vendor to make the hearing aid you need for you member.

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Prepare the Order:

• Fill out the order form

• Indicate both on the form and on the impression if there are any abnormalities

• Specify desired length of product using manufacturer’s guide

• Fold order from and place in box with impressions


Conditions that indicate an open-jaw impression would be appropriate:

• Significant jaw displacement observed externally

• Changes in ear canal shape detected during otoscopy

• Member complains of feedback or loose fitting HI

• Earmold or HI slides out of the ear

• Member reports loss of gain during jaw movement

*Note: There is a greater risk of blow-by when taking open-jaw impressions.*

The Open-Jaw Impression

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Upon completion of this lesson you will need to get ready to complete the Costco Ear Impression Certification. All apprentices have 180 days to complete this certification from their enrollment in the HAAP.

Please note: Employees are NOT allowed to take ear impressions on members until they have completed the Costco Ear Impression Certification.

Costco Ear Impression Certification

Bentler, R. A., Mueller, H. G., & Ricketts, T. (2016). Modern hearing aids: verification, outcome measures, and follow-up. San Diego, CA: Plural Publishing Inc.

Kricos, P. B. (2006, July 31). Audiologic Rehabilitation with the Geriatric Population Patricia B. Kricos. Retrieved February 14, 2018, from https://www.audiologyonline.com/articles/audiologic-rehabilitation-with-geriatric-population-976

Mueller, H. G., & Taylor, B. (2011). Fitting and Dispensing Hearing Aids. San Diego, CA: Plural Publishing.

Professional Training Textbook in Hearing Health Sciences. (2016). Plymouth, MI: Macmillan Learning Curriculum Solutions.

Professional Training Workbook in Hearing Health Sciences. (2016). Plymouth, MI: Macmillan Learning Curriculum Solutions.

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