Schlieren flow visualization: What does sound look like?
Laughing Squid posted this awesome video from NPR that explains what sound looks like.
NPR’s Skunk Bear, which is the name of their science Tumblr run by Adam Cole, explains what sound looks like using Schlieren flow visualization, a technique that chiefly uses a set of parabolic mirrors, to show air distortion. Given that sound distorts the air, it can be imaged this way. The Schlieren images for this video were provided by Mike Hargather.