Bats are so sensitive to sound waves that they actually use them to sense the shapes and location of things in their surrounding.
Sound to bats is akin to light to humans -- sound helps the bats to "see" what's around them through the technique of echo-location.
In comparison, humans can only hear sounds, not "see" them. Have you ever wonder sound or music might look like?
Watch it here:
Photo Credit: Evangrant.com