IHS Acoustics and Sound 3

Question 1

What do equal loudness contours (Fletcher-Munson curves) demonstrate about human hearing?

Accepted Answer

The ear's perceived loudness varies with both frequency and sound intensity level

Answer

The ear is equally sensitive to all frequencies at every intensity level

Answer

Louder sounds are always perceived as occurring at higher frequencies

Answer

Hearing loss affects all frequencies by the same number of decibels

Question 2

According to the inverse square law, what happens to sound pressure level when the distance from a point source is doubled?

Accepted Answer

It decreases by approximately 6 dB

Answer

It decreases by approximately 3 dB

Answer

It decreases by approximately 10 dB

Answer

It decreases by approximately 20 dB

Question 3

Why is acoustic impedance clinically relevant in audiology?

Accepted Answer

Impedance mismatches at the middle ear affect energy transfer and are evaluated via tympanometry

Answer

It determines the maximum gain setting in a programmable hearing aid

Answer

It measures the loudness discomfort level of the patient

Answer

It is used to calculate the signal-to-noise ratio inside a hearing aid

Question 4

What is the fundamental difference between analog and digital signal processing in hearing aids?

Accepted Answer

Analog processing is continuous, while digital processing samples the signal and converts it to binary data before processing

Answer

Analog hearing aids can produce louder output than digital hearing aids

Answer

Digital hearing aids only amplify high-frequency sounds above 2,000 Hz

Answer

Analog hearing aids offer more programmable channels than digital devices

Question 5

What does the 'speech banana' on an audiogram represent?

Accepted Answer

The frequency and intensity region (roughly 250–8,000 Hz, 25–65 dB HL) where most conversational speech sounds occur

Answer

The optimal frequency range identified in banana-ripening acoustic studies

Answer

The zone of frequencies that causes the greatest cochlear damage over time

Answer

The audible frequency range located above the threshold of pain

Question 6

Which frequency region is most critical for maximizing speech discrimination when fitting hearing aids?

Accepted Answer

2,000–4,000 Hz (high-frequency consonant region)

Answer

125–500 Hz (low-frequency vowel energy region)

Answer

500–1,000 Hz (mid-frequency fundamental frequency region)

Answer

6,000–8,000 Hz (very high frequency region)

Question 7

What is the occlusion effect in hearing aid acoustics?

Accepted Answer

A low-frequency resonance boost of bone-conducted sound perceived when the ear canal is blocked by an earmold or shell

Answer

Acoustic feedback caused by a poorly sealed earmold

Answer

Attenuation of high-frequency sounds produced by a deeply fitting hearing aid

Answer

An increase in ambient noise pickup caused by closing the ear canal vent