Question

A listener increases his distance from a sound source by a factor of 5.45. Assuming that the source emits sound uniformly in all directions, what is the change in the sound intensity level in dB?

Answer 1

Answer 2

intensity, I α 1/r² (inversely)

new I₁ is I/29.7025 (5.45² factor decreament)

L1= 10log(I/Iref)

L2 = 10log(I/29.7025*Iref)

= 10(log(I/Iref)) - 10log(29.7025)

sound intensity level will decrease by 14.727930 db

Answer 3

Every time you increase by r the distance you lose 5.45 dB

20logr=5.45

I = P/4pi r^2
4I = P/4pi 2r*2r