posted by dreadantlers .
Suppose a person is going to be exposed to a steady tone of frequency 8000 Hz all night (perhaps arising from noisy electronics in a nearby room. ) If this person wants their perceived room loudness level to be a very quiet 10 phon (in order to sleep easily), what is the maximum sound intensity level (in dB) that we should have in the room? Use Fig 6.12 to help you answer this question. Once again, you can round to the nearest 5 dB. Do not enter units. If you think the best answer is 13 dB, enter 15.