So what is sound? You can’t see it, you can’t touch it. How can something like paint or thermally bonded cotton stop it from travelling through a space Sound is created when vibrations are transmitted through solid, gas and liquid mediums, like squeaking floor boards, air or water. To create sound that is audible to human ears, sound energy moves the molecules of the substance through which it is travelling and creates sound waves that spread in a circular pattern like ripples in a pond. As sound waves move further away from their source their intensity naturally becomes less intense.
Sound is a lot like water. It doesn’t have a shape or form so it molds itself to its surroundings and, like water, can be absorbed by some materials and contained by others. This is why sound absorbing and soundproofing materials can stop the transfer of sound within a space, or from one space to another.