Question

why does sound become faint with distance?

Answer 1

sound become faint with distance due to loss of audible power

Answer 2

Two things are happening:

1. Sound spreads in a sphere, like a balloon that gets inflated. As the sound spreads over a larger area the sound gets fainter.
2. As you are moving away from the source of the sound it takes more and more time between the arrival of the start of a soundwave and the end of a soundwave. This will cause the sound to go lower and lower but also to sound fainter.