Two physicists developed a new technology called AudioScope that apparently enables you to zoom in on sounds in huge, loud places like sports arenas or lecture halls. Physicists Morgan Kjølerbakken and Vibeke Jahr, formerly of the University of Oslo, were were experimenting with sonar when they hit upon the idea for the AudioScope, which is based on a circular array of 300 microphones and a video camera. They've now launched a company, Squarehead, to commercialize the system. From New Scientist:
The AudioScope software then calculates the time it would take for sound emanating from that point to reach each microphone in the circular array, and digitally corrects each audio feed to synchronise them with that spot.
"If we correct the audio arriving at three microphones then we have a signal that is three times as strong," says Kjølerbakken. Doing the same thing with 300 microphones can make a single conversation audible even in a stadium full of sports fans.