Under magnetic resonance imaging, they observed the mechanics of how the artists make the distinctive beats that sound like percussion instruments using only their mouths. In gritty black and white , their tongues leap and flip; a sound like a snare drum snaps out.

The research, based on scans of five different beatboxers, was presented Wednesday at the Acoustical Society of America. The scientists, with specialties in computer science, engineering and linguistics, are comparing the movements in beatboxing to those used to make speech. They hope to learn more about how the human body produces language and to develop algorithms that can accurately describe the dynamics of the vocal tract.