IHS Instrument Selection 3 — Questions and Answers
Question 1: What does the acronym WDRC refer to in hearing instrument signal processing?
- Wide Dynamic Range Compression (Correct answer)
- Wireless Digital Reception Circuit
- Wide Directional Range Control
- Weighted Digital Response Calibration
Correct answer: Wide Dynamic Range Compression
WDRC (Wide Dynamic Range Compression) amplifies soft sounds more than loud sounds to restore the compressed dynamic range typical of sensorineural hearing loss.
Question 2: A patient understands speech well in quiet but struggles in restaurants. Which technology feature should be PRIORITIZED during instrument selection?
- Increased maximum output (MPO)
- Directional microphone system with digital noise reduction (Correct answer)
- Telecoil for induction loop systems
- Extended low-frequency amplification
Correct answer: Directional microphone system with digital noise reduction
Directional microphones and noise reduction algorithms specifically target improving the speech-to-noise ratio in environments like restaurants.
Question 3: Which compression parameter determines how quickly a hearing aid responds to a sudden loud sound?
- Compression ratio
- Compression kneepoint (threshold)
- Attack time (Correct answer)
- Release time
Correct answer: Attack time
Attack time is the speed at which the compressor engages to reduce gain when the input signal exceeds the compression threshold.
Question 4: A patient with bothersome tinnitus is being fitted with hearing aids. Which technology feature may provide additional relief beyond standard amplification?
- Frequency compression
- Built-in tinnitus sound therapy programs (Correct answer)
- Extended high-frequency amplification
- Binaural wireless synchronization
Correct answer: Built-in tinnitus sound therapy programs
Many modern hearing aids include dedicated tinnitus therapy programs that generate masking or soothing sounds to reduce tinnitus perception.
Question 5: What is the PRIMARY purpose of a feedback cancellation algorithm in a digital hearing aid?
- Reduce the instrument's maximum output level
- Detect and suppress acoustic feedback whistling before it becomes audible (Correct answer)
- Improve battery efficiency
- Enhance directional microphone polar pattern
Correct answer: Detect and suppress acoustic feedback whistling before it becomes audible
Feedback cancellation continuously monitors for feedback and applies an inverse signal to cancel the whistle before the patient or listener hears it.
Question 6: Frequency lowering technology is MOST beneficial for patients with which audiometric profile?
- Flat mild hearing loss across all frequencies
- Severe-to-profound high-frequency hearing loss with poor audibility above 2000 Hz (Correct answer)
- Low-frequency hearing loss with normal high-frequency thresholds
- Symmetrical moderate hearing loss
Correct answer: Severe-to-profound high-frequency hearing loss with poor audibility above 2000 Hz
Frequency lowering shifts high-frequency speech cues (such as /s/ and /sh/) to lower frequencies where residual hearing exists, improving consonant audibility.
Question 7: A hearing instrument with multiple memory programs is MOST useful for which type of patient?
- A patient with stable hearing loss and a single daily listening environment
- A patient who regularly moves between quiet, noisy, music, and telephone listening situations (Correct answer)
- A patient who prefers a fully automatic single-program instrument
- A patient with unilateral hearing loss
Correct answer: A patient who regularly moves between quiet, noisy, music, and telephone listening situations
Multiple memories allow optimized settings for distinct acoustic environments, enabling the patient or automatic switching to match the current listening situation.
IHS Instrument Selection 3
What does the acronym WDRC refer to in hearing instrument signal processing?