The 325 microphones monster

An innovation created by two Norwegian physicists allows to zoom on conversations inside a crowd. Great for TV coverage of sport game, but worryingly precise if you start seeing this deployed in a surveillance context...

Squarehead’s new system is like bullet-time for sound. 325 microphones sit in a carbon-fiber disk above the stadium, and a wide-angle camera looks down on the scene from the center of this disk. All the operator has to do is pinpoint a spot on the court or field using the screen, and the Audioscope works out how far that spot is from each of the mics, corrects for delay and then synchronizes the audio from all 315 of them. The result is a microphone that can pick out the pop of a bubblegum bubble in the middle of a basketball game, as you can see in this video.

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