Sound can travel in any medium that is sufficiently dense for motion energy to be transferred between atoms in the medium.did you mean light waves?
last I heard....sound cannot travel in space
According to theory, when the universe was very dense, very early on, there were SOUND waves in the universe, the pattern of which helped to set the distribution of matter later on...If you're not aware of this aspect of cosmological theory, I suggest you watch a few more documentaries on the origins of the universe...or maybe, read some of the books and articles that have been written...