HAC Digital Signal Processing in Hearing Aids 5

Question 1

In a DSP hearing aid, what is the 'equivalent input noise' (EIN) specification used to evaluate?

Accepted Answer

The noise floor introduced by the hearing aid's own microphone and electronics

Answer

The background noise level in the patient's typical listening environment

Answer

The amount of noise the compressor introduces during signal processing

Answer

The radio frequency interference level during wireless streaming

Question 2

Which hearing aid feature uses DSP to compare microphone signals and identify the location of a speaking talker?

Accepted Answer

Spatial noise reduction / beamsteering

Answer

Acoustic feedback management

Answer

Frequency lowering

Answer

Output limiting

Question 3

What is 'harmonic distortion' in the context of hearing aid amplifier performance?

Accepted Answer

The creation of unwanted frequency components at multiples of the original signal frequency

Answer

Distortion caused by mismatched harmonic filters in the DSP chain

Answer

The acoustic resonance of the ear canal at harmonic frequencies

Answer

Phase distortion introduced by multi-channel processing

Question 4

A clinician is adjusting the 'compression knee-point' (threshold kneepoint) in fitting software. Lowering the kneepoint will:

Accepted Answer

Cause compression to engage at softer input levels, amplifying more of the dynamic range

Answer

Increase the maximum output level of the hearing aid

Answer

Make the compression attack time faster

Answer

Reduce the number of frequency bands used in processing

Question 5

What technology allows modern hearing aids to stream audio directly from smartphones without an intermediate streaming device?

Accepted Answer

Made for iPhone (MFi) / ASHA (Audio Streaming for Hearing Aids) Bluetooth protocols

Answer

Near Field Communication (NFC)

Answer

FM radio reception built into the DSP

Answer

Infrared data association (IrDA)

Question 6

In digital hearing aids, 'datalogging' refers to:

Accepted Answer

Recording environmental statistics and usage data stored in the hearing aid's memory

Answer

Exporting the patient's audiogram to an electronic health record

Answer

Streaming audio from the hearing aid to a cloud server for analysis

Answer

Logging errors in the DSP firmware for manufacturer diagnostics

Question 7

Which of the following is a key difference between 'linear amplification' and 'non-linear amplification' in DSP hearing aids?

Accepted Answer

Linear amplification applies the same gain regardless of input level; non-linear varies gain based on input level

Answer

Linear amplification processes all frequency bands equally; non-linear uses different bands

Answer

Linear amplification is only used for music; non-linear is for speech

Answer

Linear amplification requires more DSP processing power than non-linear