What happens to sound energy when it hits a vacuum?

[Lmlodninja]

What happens to sound when it hits a vacuum? Because there is nothing for the sound wave to vibrate against, what happens to the energy?

 

[DrClaude]

The sound wave will get reflected back.

 

[anorlunda]

It depends on what you mean by sound. There are shock waves and other winds in nebula. The following thread and the "Similar Discussions" list at the bottom of this page may help.

https://www.physicsforums.com/threads/interstellar-speed-of-sound.683322/#post-4334974

 

[Lmlodninja]

Anorlunda, what I mean by sound is vibrations that travel through the air or another medium and can be heard when they reach a person's or animal's ear.