Noah Vawter, a PhD candidate in media arts and sciences, is on a mission to turn the personal-audio experience on its ear with a small device that he calls Ambient Addition. Instead of tuning out noises from the world around us, it creates music that is based on them.

Each Ambient Addition headset has two microphones that detect noises–a door’s closing, say–and a tiny digital signal­-­processing chip that analyzes them. The device acts as a phase vocoder–essentially, a stereo graphic equalizer on steroids. “With a phase vocoder, you can say, ‘I want everything to sound like [the note] A right now,’” says Vawter. After recording samples of a given environment’s sounds, the device constructs patterns based on them, lending rhythm and harmony to a dissonant world.

Users hear sustained chords with a slight vibrato; they change periodically, and when a staccato noise–like the dropping of a two-by-four at a construction site–intrudes, it’s digitally processed to fit in with the chord being played. It may also be recorded and mixed on the fly into new rhythmic patterns.

A self-taught bass guitarist, Vawter, 32, who’s studying with the Computing Culture Research Group at MIT’s Media Lab, had observed dissonant chords in environmental sounds and conceived Ambient Addition as a way to make street noise more harmonious. The device, which served as the core of his master’s thesis, was completed in May 2006.

Along the way, Vawter has used it to explore the cacophony of everyday din. “I find that [Ambient Addition] affects how I interact with my environment,” he says. He suspects that it would have the same effect on others: “Instead of avoiding a construction site, now they’ll make sure they walk past it. In an ironic way, you want the world to be noisier.”

Vawter has already made some noise with a major cell-phone company. He’s been asked to tweak an existing phone so that it can double as an Ambient Addition device.