HAC HAC Hearing Aid Anatomy & Components 2

Question 1

What does WDRC stand for in hearing aid technology?

Accepted Answer

Wide Dynamic Range Compression

Answer

Wide Dynamic Range Compression (WDRC) applies more gain for soft sounds and less gain for loud sounds, accommodating the reduced dynamic range typical of sensorineural hearing loss.

Question 2

What is the compression knee point (threshold) in a hearing aid?

Accepted Answer

The input level at which compression begins to operate

Answer

The compression knee point is the input SPL above which the hearing aid begins reducing gain, transitioning from linear to compressive amplification.

Question 3

What does OSPL90 (or SSPL90) measure in hearing aid specifications?

Accepted Answer

Maximum output sound pressure level with a 90 dB SPL input sweep

Answer

OSPL90 is the output sound pressure level curve measured across frequencies with a 90 dB SPL input, defining the hearing aid's maximum saturation output.

Question 4

What is the primary role of the digital signal processor (DSP) chip in a modern hearing aid?

Accepted Answer

Process the electrical signal to apply amplification, noise reduction, feedback cancellation, and other features

Answer

The DSP chip performs all real-time digital processing including multi-channel amplification, noise reduction, feedback suppression, and feature management.

Question 5

Which term describes the high-pitched squealing sound produced when amplified sound from the receiver re-enters the microphone?

Accepted Answer

Acoustic feedback

Answer

Acoustic feedback occurs when amplified sound leaks from the receiver back into the microphone, creating an uncontrolled positive gain loop that produces squealing.

(HAC) Hearing Aid Certification Practice Test

(HAC) Hearing Aid Certification Practice Test

HAC HAC Hearing Aid Anatomy & Components 2