Is overall loudness proportional to the number of speakers? F. E., if I use 4 identical sound devices instead of one, playing the same sound sample... Will they sound 4 times louder?

a. No. The overall loudness is not proportional to the number of speakers.

b. No, it will not sound 4 times louder.

Explanation:

a. Loudness is the quality of how loud or soft the sound is. Since loudness is proportional to intensity and intensity proportional to the amplitude of the sound, the overall loudness of the sound would not be proportional to the number of speakers.

Since the sound from each speakers adds by superposition, their phases might be different but their amplitudes the same. So, the resultant wave from the four speakers has the same amplitude as the wave from one speaker. And, since loudness is proportional to amplitude, the loudness of the resultant wave is equal to the loudness of each individual speaker.

So, the loudness is not proportional to the number of speakers.

b. No, it will not sound 4 times louder.

This is because loudness is a function of amplitude.

Since the devices are identical and playing the same sound, their amplitudes are the same. They will thus add by superposition to generate a resultant wave which has an amplitude the same as each individual wave.

Since the amplitude of the resultant wave is the same and not an addition of each individual amplitude, the resultant wave does not sound 4 times louder.

b) 10 minutes

girls stopped for 10 minutes.

d. air pressure decreases as altitude increases.