Final Exam Review Flashcards
What is the Lybarger prescription?
“Half-gain” rule
1944
What is the POGO and POGO II prescription?
POGO (1983) POGO II (1988)
Half-gain + low-frequency correction factor
What is the Berger prescription?
More than half gain for middle frequencies
1979, 1988
What is the Libby prescription?
Gain about 1/3 of the hearing loss
1986
What is the NAL-R prescription?
LTASS placed @ MCL
Intelligibility is assumed to be maximized when all bands of speech are perceived to have the same loudness
1986
What is the NAL-RP prescription?
Change in slope from 46% to 31%
What is the DSL prescription?
Achieve audibility & comfort in each frequency region
What is the Cambridge prescritpion?
Essentially the same rationale as NAL
Which prescriptive method provides the most gain?
From greatest to least amount of gain:
- Berger
- DSL
- POGO
- NAL-R
- Libby
What is the IHAFF/Contour?
IHAFF- Independent Hearing Aid Fitting Form
- IHAFF protocol aims to normalize loudness at each frequency
- Recommends CT of 40-45 dB
What is the FIG6?
- Developed by Killon & Fikret-Pasa (1993)
- Use of average loudness data
- Loudness normalization
What is the DSL [i/o]?
Goal: restore amplification characteristics so all acoustic signals available to WNL listener available to HoH listener within auditory DR
Loudness equalization
What is the DSL 5.0?
Adjustment to gain: lows, mids, highs
- Correction for conductive hearing loss
- Correction for binaural amplification
What is the NAL-NL1 prescritpion?
- Underlying rationale = maximize speech intelligibility (not to restore normal loudness) but with overall loudness of speech at any level being no more than perceived by a listener with normal hearing
Two theoretical models used:
- Speech intelligibility index
- Method for calculating loudness
- Prescribed gain for 70 dB input similar to NAL-RP
What are difficult issues related to selecting a prescription method?
- Acclimatization & adaptation gain & frequency response
- Patients adapt to the tinny sound of the hearing aids and get more benefit
- The more the patient listens with amplification, the more they adapt - Preferred loudness
- Hearing aid users prefer 3-4 dB less than what’s prescribed - Dead regions
- Damage to the inner hair cells; no signal going to the brain
- Sending sound to dead regions results in distortion - Severe hearing loss, effective audibility, & high-frequency amplification
How can you verify hearing aid performance?
- Probe microphone measurements
- Real ear measurements with speakers in front and in back of the patient
Why do you need to verify hearing aid performance?
- For quality control, to make sure they are getting sufficient volume to hear speech
- Also used to counsel the patient
What is the primary goal of orientation?
PHAST (Desjardins & Doherty, 2009)
- Remove your hearing aid
- Open the battery door
- Change the hearing aid battery
- Demonstrate how you clean your hearing aid
- Put your hearing aids in
- Turn up the volume
- How do you use the telephone with your hearing aids
- How do you use the noise program/directional microphone
What are appropriate expectations for new hearing aid users?
Listening in quiet
- We expect patients will hear better in quiet situations
Background noise
- They should hear better in background noise with hearing aids (if it’s a moderate level)
- They will not hear better in an extremely noisy situation
- Their hearing in loud background noise should be no worse than listening without their hearing aids
- They should expect to hear soft speech, average speech should be comfortable, and loud speech should not be uncomfortable
Earmold/earshell comfort
- It should be comfortable to wear for the patient
Own Voice
- They should expect that their own voice is acceptable to them (counsel them on getting used to the occlusion effect)
Acoustic Feedback
- There should be no feedback during regular use
- Not unusual for older patients to put their hearing aids on upside down or on opposite ears