Question

What is the difference in intensity for two sounds that are 40 dB apart?

Answer 1

the difference of 10 dB is considered as having 10 times the intensity, so difference of 40 dB means :

=》10 × 10 × 10 × 10

=》10000 times

so the the intensity of one sound is 10000 times the other one.

Answer 2

The Threshold of Hearing and the Decibel Scale

The faintest sound that the typical human ear can detect has an intensity of 1*10-12 W/m2.