IHS Instrument Fitting 5 — Questions and Answers
Question 1: During a hearing aid fitting verification, the functional gain measurement is performed by comparing:
- Aided and unaided soundfield thresholds (Correct answer)
- Real-ear and 2-cc coupler responses
- REIG and REUG
- Audiogram and loudness scaling scores
Correct answer: Aided and unaided soundfield thresholds
Functional gain is the difference in dB between unaided and aided soundfield pure-tone thresholds, measuring how much audibility the hearing aid adds.
Question 2: A patient with a steeply sloping high-frequency hearing loss is fitted with open-fit RIC devices. A common complaint is difficulty understanding speech in noise. The MOST appropriate adjustment is:
- Increase low-frequency gain
- Switch to a closed dome or custom earmold (Correct answer)
- Reduce the MPO
- Increase compression attack time
Correct answer: Switch to a closed dome or custom earmold
Switching to a closed dome or custom earmold improves low-to-mid frequency retention in the canal, reducing the low-frequency noise that leaks in through the open vent and competing with speech.
Question 3: Which outcome measure is specifically designed to assess hearing aid benefit in four listening situations important to the patient?
- APHAB (Abbreviated Profile of Hearing Aid Benefit) (Correct answer)
- COSI (Client Oriented Scale of Improvement)
- HHIE (Hearing Handicap Inventory for the Elderly)
- IOI-HA (International Outcome Inventory for Hearing Aids)
Correct answer: APHAB (Abbreviated Profile of Hearing Aid Benefit)
The APHAB measures benefit across four subscales: Ease of Communication, Background Noise, Reverberation, and Aversiveness of Sound.
Question 4: For a patient whose audiogram shows a 'cookie bite' configuration (greatest loss in the mid frequencies), the fitting challenge is primarily:
- Avoiding feedback in the low frequencies
- Providing mid-frequency gain without over-amplifying highs and lows (Correct answer)
- Selecting a power BTE style
- Using a T-coil for all environments
Correct answer: Providing mid-frequency gain without over-amplifying highs and lows
Cookie bite losses require selective mid-frequency amplification while keeping low and high-frequency gain appropriate to avoid distortion or discomfort.
Question 5: When documenting a hearing aid fitting for a minor patient, which additional step is legally and ethically required compared to adult fittings?
- A second audiologist must co-sign the fitting
- Parental or guardian informed consent must be obtained (Correct answer)
- The prescription must be mailed to a physician
- A bone conduction test must be repeated at fitting
Correct answer: Parental or guardian informed consent must be obtained
Fitting hearing devices on minors requires informed consent from a parent or legal guardian, as the child cannot legally consent on their own behalf.
Question 6: Which of the following is the MOST important reason to perform real-ear measurement rather than relying solely on manufacturer first-fit settings?
- To check the battery voltage level
- To verify the hearing aid meets target gain for the individual's ear canal acoustics (Correct answer)
- To measure the compression ratio in situ
- To confirm wireless streaming functionality
Correct answer: To verify the hearing aid meets target gain for the individual's ear canal acoustics
Individual ear canal acoustics vary significantly; real-ear measurements verify that the prescribed target gain is actually delivered at the tympanic membrane for that specific patient.
Question 7: A dispensing professional is troubleshooting intermittent sound from a BTE hearing aid. After ruling out the battery and programming, the NEXT most likely cause to check is:
- Broken or corroded tubing and earmold connection (Correct answer)
- Feedback suppression algorithm
- Directional microphone mode
- Telecoil interference
Correct answer: Broken or corroded tubing and earmold connection
Intermittent sound in BTE devices is frequently caused by a cracked, blocked, or corroded acoustic tube or earhook connection disrupting sound transmission.
IHS Instrument Fitting 5
During a hearing aid fitting verification, the functional gain measurement is performed by comparing: