# B Why does loudness of sound vary as square of amplitude?

1. Mar 9, 2016

### Fiona Rozario

Why does loudness of sound vary as square of amplitude? Why not cube of amplitude or just amplitude?

2. Mar 9, 2016

### Qwertywerty

You obtain this result on the mathematical derivation of the intensity.

Edit : This is for the intensity of the sound wave. The loudness(in dB), is measured as β = log(I/I0)dB, where I0 = 10-12W/m2.

You seem to be confused between intensity and loudness

Last edited: Mar 10, 2016
3. Mar 10, 2016

### Svein

Loudness is a much more complicated thing, as it (usually) refers to what the human ear perceives.