IHS Acoustics and Sound 5

Question 1

Which type of microphone converts sound pressure variations into electrical signals through the movement of a coil within a magnetic field?

Accepted Answer

Dynamic (moving-coil) microphone

Answer

A dynamic microphone uses electromagnetic induction: a diaphragm attached to a coil moves within a magnetic field, generating a voltage.

Question 2

The critical band concept in psychoacoustics refers to:

Accepted Answer

A frequency range within which two tones interact and mask each other

Answer

A critical band is a frequency region of the cochlear basilar membrane within which stimuli interact, causing masking and affecting loudness perception.

Question 3

Harmonic distortion in a hearing aid occurs when the device produces:

Accepted Answer

Output frequencies that are integer multiples of the input frequency

Answer

Harmonic distortion adds overtones at whole-number multiples (harmonics) of the input frequency, degrading sound quality.

Question 4

Reverberation time (RT60) is defined as the time required for sound pressure level to decrease by:

Accepted Answer

60 dB after the source stops

Answer

RT60 is the time it takes for the sound energy in a room to decay by 60 dB once the sound source ceases.

Question 5

What term describes the frequency at which a structure naturally vibrates when excited, with minimal energy input?

Accepted Answer

Resonant frequency

Answer

The resonant frequency is the natural vibration frequency of a structure; at this frequency, even small driving forces produce large oscillations.

IHS - International Hearing Society Practice Test

IHS - International Hearing Society Practice Test

IHS Acoustics and Sound 5