U.S. Researcher Captures Sound In Narrow Beam

"All the others universities, even [those who] specialized in acoustics, thought I was crazy, saying that it couldn't work," said shaven-headed Pompei, 27. "Here, they just told me: What do you need?"

Pompei, an acoustics expert since his teens, wanted to develop a way to direct beams of sound in the same way light is beamed by torches and spotlights. "You get into the beam, you hear. You move a few centimeters, you don't," he explained.

MediaLab is like no other research center. Students and researchers are encouraged to follow their whims - to explore, to play and to fantasize with the best toys at their disposal. Within months of joining the program, Pompei came up with his prototype for the "Audio Spotlight," a sleek black transmitter with a laser to direct the sound beam, linked to a box the size of a hi-fi amplifier.

His project hinged on the ability of air to vibrate, generating a narrow three-degree band of audible sound from an ultra-sound ray. "Traditional loudspeakers are like a light bulb. The Audio Spotlight is like a laser," he said. "We're testing applications in collaboration with sponsors of the MediaLab for eventual commercial release. Could be in six months or two years."

Private contributors, mostly big multinational corporations, furnish 95% of MediaLab's annual budget of $35 million. In return, they get rights to use MediaLab inventions without paying royalties.

Pompei can already visualize some application for his invention. The U.S. Defense Department has been quick to seize on the implications, and is interested in the sound spotlight.

For the time being he is having fun. From the third floor of the I.M. Pei-designed MediaLab building, he sends a beam of jazz directly into the ear of a fellow student on the ground floor. She raises her eyes and smiles. Bounced off a wall or ceiling, the beam bathes the room in sound, like light reflected from mirrors.