Midterm Exam Flashcards
What are the different styles of hearing aids?
Completely in the canal - CIC Mini Canal - MC In the Canal - ITC Half Shell - HS In the Ear - ITE Mini Behind the Ear - Mini BTE Behind the Ear - BTE
Which hearing aids are appropriate for a mild loss?
All styles OK
Vent is important, beware of occlusion effect
What types of hearing aids are appropriate for a mild/moderate loss?
All styles OK
Vent is important, except in CIC
What types of hearing aids are appropriate for a moderate loss?
All styles are OK except for the mini canal (high risk)
Fitting flexibility or no pots(?) available
What types of aids are appropriate for a moderate/severe loss?
High Risk - ITC
No mini canal
Feedback, max gain is most important consideration
What type of aid is appropriate for a severe loss?
Half Shell is High Risk CIC is High Risk NO In the Canal NO mini canal - feedback, max gain most important consideration
What types of aids are appropriate for a severe/profound loss?
BTE mostly,
ITE with High Risk
- feedback, max gain most important consideration
What types of aids are most appropriate with a profound loss?
BTE only
not enough power in smaller aids
What are the four difficult hearing loss configurations to fit with hearing aids?
- cookie bite
- precipitous
- reserve slope (depending on degree)
- NL - No loss with ski slope
Why is a ‘Cookie Bite’ hearing loss hard to fit with hearing aids?
ITC - high risk
NO mini canal
Venting is very important
Why are precipitous losses hard to fit with hearing aids?
No Half Shell No In the Canal No Mini Canal CIC - High Risk Beware of Occlusion Effect and PBK
Why is a reverse slope loss hard to fit with hearing aids?
Depending on Degree
No Mini Canal
Venting important except in CICs
Why is NL (no loss with ski slope) difficult to fit with hearing aids?
High Risk for Half Shells No ITC No mini canal Occlusion effect and Pbk most important Venting important
What is the difference between a BTE and a mini BTE?
Mini BTE has a lower gain and output than the BTE in the matrix and fitting range
What is the “Matrix”
- The Matrix gives the peak output (in dB SPL), and peak gain (in dB) the aid can produce.
- Aid can be programed to lower values for a particular patient if need be.
- NOTE: bottom of fitting range may be optimistic
Receiver in the Ear (RITE) Hearing Aids
- Receiver enclosed in a soft dome or custom shell
- External receiver requires less space in the aid, smaller HA
- Theoretically less feedback, because the receiver and the mic are separated (“body aid effect”)
- Tubing is wire, so sound can’t leak through the tubing -> less feedback, no tubing resistance
What is MSG?
- Maximum stable gain
- This is the max insertion gain that can be provided without audible feedback oscillation with feedback cancelation on
What are some manual dexterity options?
- Helix lock, ITEs only
- Canal lock, available on CICs
- removal filament line
- stacked or raised volume control
- removal notch
What are some wax prevention options?
- spring wax guard
- wax trap
- canal bell
- extended receiver canal
Why would you use a body aid?
used only in rare cases where BTE gain is not sufficient and/or can not get required gain without feedback
*these days almost never used because of feedback reduction and cochlear implants
Lyric Extended Wear CICs
Deeply inserted into bony portion of the canal (~ 4 mm from TM)
- deep mic insertion allows use of pinna and concha cues (resonance and localization)
- smaller residual volume requires less gain
CROS Link
- uses a transmitter and receiver
- BTE transmitter on the poorer ear, sends signal through FM to a receiver on a BTE in good/better ear.
- Can fit BTEs of a variety of manufacturers with the appropriate audio shoe
- even though the sound isn’t being put into the bad ear, use a custom (open) mold for better retention
- BI-CROS sends sound across but also amplifies
What information do you have access to when deciding on the correct amplification device for the patient?
- Case History (start thinking about this while taking case history)
- Age - most relevant with child
- Ear size/shape, from otoscopy may limit some styles like CIC
- Dexterity or vision limitations (from history)
- Audiogram
- Loudness Discomfort Levels (LDLs)
- Speech discrimination in quiet and noise
- Communication needs from history and from pre-fitting questionnaire (to supplement history)
Medical Referral Criteria
- Deformity of the outer ear
- Significant cerumen accumulation
- history of drainage within 90 days
- history of sudden loss within 90 days
- acute or chronic dizziness
- unilateral loss of sudden/rapid onset within 90 days
- ear pain or discomfort
- conductive component/ air-bone gap
What is the APHAB?
- abbreviated profile of hearing aid benefit
- one possible pre-fit questionnaire
- can provide information useful in selection or combined with post-fitting APHAB to measure benefit
- results are measured in % problematic, so higher numbers are WORSE - more trouble understanding in those situations
What are the four sub-scales of the APHAB?
Ease of Communication (EC)
Reverberation (RV)
Background Noise (BN)
Aversiveness of Sounds (AV)
Which of the APHAB sub-scales can be predicted by the audiogram?
- Audiogram predicts less than 1/2 of the variance of EC and RV and DOES NOT predict BN and AV.
What is the COSI?
- Client Oriented Scale of Improvement
- allows the patient to identify situations in which they need improvement
- same situations will be evaluated post-fitting to measure benefit
QuickSIN
- Audiometric battery should include a speech in noise measure
- helps you decide on level of noise reduction, directional mics, ALDs required to improve communication
- mild or moderate = need noise reducing hearing aids (directional mics)
- severe = need ALD
What should you consider when you are fitting only one ear of an asymmetric loss?
- will fitting the better ear make more sounds audible/clearer?
- will fitting the worse ear make more sounds (bilaterally) more audible (i.e. make the bad ear more useful) & give better sound localization
- (but consider limitations of poor discrimination when counseling)
In a symmetrical loss, do you fit one ear or two?
- fit both ears unless you have a good reason not to
- demonstrated binaural interference
- contra-indications
If asymmetrical loss, do you fit one ear or two?
- fit both ears when audio-metrically appropriate