Scientists in Norway at Squarehead have developed a technology called AudioScope that apparently enables you to zoom in on sounds in huge, loud places like sports arenas or lecture halls.
AudioScope is based on the same principle as sonar. A dish with an array of microphones can locate and record sound anywhere in a large room. A speaker’s voice in an auditorium is picked up by all the microphones on the dish. Depending on the position of each microphone, the sound will reach them at a slightly different time. We use this to our advantage. To compensate for this deviation, we add delays to the microphones. Thus we are able to receive the audio from all of the microphones at the same time. When all the adjusted signals are combined we get an amplified signal. This technique is
called beam-forming, and when this technique is applied to hundreds of microphones the result is a tremendous signal boost.The human brain can do this with just two microphones – your ears. If someone calls out your name in the street, you usually turn your head in that direction without thinking. AudioScope can do the same. It just uses a few more “ears” to achieve the same result.
Video after the jump.
New Scientist has more.