There are five general senses: touch for feels, taste for food, smell for avoiding trash, hearing for sounds, and, of course, eyesight for visualizing the very waves making up that sound. [PlasmatronX] drives that last point home with his camera for sound waves, that’s even able to capture constructive and destructive interference. (Video, embedded below.)
You may have heard of Schlieren imaging, which is usually used to capture the movement of air currents caused by heat sources. [PlasmatronX] sets up a concave mirror to amplify the refraction of different densities of air, only unlike traditional Schlieren setups, he’s after the different densities of air caused by the pressure waves that we interpret as sound.

