If you’ve ever seen a graphical representation of a sound, you are probably familiar with what it looks like: hundreds of steep, tightly packed peaks and valleys, all of different heights, moving above and below a common line of symmetry that cuts horizontally through the middle. “When a sound travels through the air, it basically sets the molecules around us in motion, using sound pressure to create sort of a wave,” says Waisman researcher Michaela Warnecke, PhD.