Question

What is the approximate sound intensity level in decibels of a 600-Hz tone if it has a loudness of 20 phons? If it has a loudness of 70 phons?

a) 60 dB, 80 dB
b) 65 dB, 85 dB
c) 70 dB, 90 dB
d) 75 dB, 95 dB

Answer 1

A 600-Hz tone with a loudness of 20 phons would correspond to approximately 60 dB, and a 600-Hz tone with a loudness of 70 phons would correspond to approximately 80 dB.

So the correct answer would be Option a) 60 dB, 80 dB.

Step-by-step explanation:

The sound intensity level in decibels (dB) can be related to the perceived loudness, measured in phons, but they are not the same. A phon is a unit of loudness level for pure tones, and it corresponds to the dB level at a frequency of 1000 Hz. To estimate the sound intensity level in decibels for tones at other frequencies with a given loudness in phons, a standard equal-loudness contour chart is typically used. Based on such charts:

• A 600-Hz tone with a loudness of 20 phons would approximately correspond to 60 dB.
• A 600-Hz tone with a loudness of 70 phons would approximately correspond to 80 dB.

So the correct answer would be Option a) 60 dB, 80 dB.