This video shows the song known as "Equation" or "Formula" (its actual title can be seen here) run through a spectrograph program.

Richard James has incorporated hidden images in some of his songs. This is the most notable one. His face can be seen at the end of the song. There are supposedly other embedded images within this song, but his face is the most obvious one.

This is done by using a program to encode visual images into soundwaves. The particular program used by Richard is one for the Mac called MetaSynth.