It’s nice to think of the world as a symphony, but most of the time it’s cacophony — clashing noises coming from all around us.
“When you listen to sound over loudspeakers,” says F. Joseph Pompei at the Media Lab at the Massachusetts Institute of Technology, “you don’t have any control over where the sound goes. Sometimes you don’t want it to go everywhere.”
Pompei has devised a way to solve that problem. He has figured out how to “steer” sounds by aiming them only where he wants them to go with a device he calls an “Audio Spotlight.”
A Beam of Sound
It looks like a disc-shaped loudspeaker, trailing a wire, with a small laser guide-beam mounted in the middle. When Pompei points the flat side of the disc in your direction, you hear whatever sound he’s chosen to play for you — perhaps jazz from a CD.
But when he turns the disc away, the sound fades almost to nothing. It’s markedly different from a conventional speaker, whose orientation makes much less difference.