How far can sound travel?

[LordGrover]

Keep your ears open: click.

article said:

An F1 engine by itself makes a big noise - about 120 decibels. Add in the 180 decibels expected from the hybrid rocket in full voice and there should be quite a roar drifting over Newquay in the coming months.

[FarmyardPants]

GokTweed said:

No i don't think so, it's a wave so it will carry on until it gets cancelled out by interference

The wave is carried by a the knock on effect of a higher density region of molecules colliding with their neighbours. The difference in density decreases as the wave propagates. There will come a point where the energy to be imparted to the neighbouring molecule is less than the temperature difference of the molecule vibrations. At this point there is no further propagation and the "last" molecule does not collide but, having failed to do so, oscillates instead and takes on an infinitesimal amount of heat. This, too, will quickly radiate to neighbours which stray close enough. There is then no wave left.