I didn't know where I should ask this so I just did it here.

 

My book that I am reading on Light & Sound Waves states the following.

 

"Consider what happens when waves of sound move through the billions upon billions of particles that make up the air. A disturbance -- the ringing of a bell, a revolver shot, a mewoing of a cat -- causes the particles of the air nearest the disturbance (call them A particles) to bump into there neighbors, which we shall call B particles bump into the adjacent C particles and so on. The series of collisions brings about variations in pressure of the air; the variations are transmitted through the air at the rate of roughly a mile in five seconds and reach the ear drum of the listener."

 

So does this mean if we could remove all the air on Earth there would be no sound?

Yes. Also, sound waves travel faster in water, for example.

 

And to tackle what might be your next question: Lightwaves do not need a medium to travel in. The mathematical description of both light and sound as waves led to the assumption that there would also be a medium that light propagates in. This medium was called aether. It, however, turned out that the assumtion of such a medium leads to problems and so the current view of lightwaves does not imply this.