The Visual Microphone: Passive Recovery Of Sound From Video

Description:  In this amazing demonstration researchers are able to extract audio from the video of an object (a plant, an empty bag, etc.) in same room as the sound. The sound waves vibrate the object which is made visible through tiny movements processed with a graphic algorithm. This could be used as a phenomenon in a unit on sounds, waves, and information.

Web Resource:  Extracting audio from visual information - MIT News