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Privacy Hardware Technology

High-Tech Microphone Picks Voices From a Crowd 221

Posted by Soulskill
from the watch-your-mouth dept.
JerryQ writes with news of an impressive audio detection system from a company called Squarehead that was demonstrated during a professional basketball game. According to Wired, "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..."
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High-Tech Microphone Picks Voices From a Crowd

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  • Nothing to hide (Score:2, Interesting)

    by Anonymous Coward on Monday October 11, 2010 @02:25PM (#33862178)

    Wow... why limit it to just stadiums? You could have arrays of these things lining every street and every mall! Just imagine how many terrorists you could catch by processing all the millions/billions of conversations going on in public places. All that data would be handy for collecting evidence against criminals too, you just go back through your chatlogs (all indexed per-person with voice/facial recognition) and dig up every conversation they've ever had outside.

  • by Obfuscant (592200) on Monday October 11, 2010 @02:37PM (#33862302)
    This sounds like beamforming. Submarines do this. Works great.

    So THAT'S what that large, grey cylindrical object hanging over the heads of the crowd at the last professional basketball game I went to was. I always wondered...

    I wonder if they heard me saying "I wonder what that large grey cylindrical object hanging over our heads is", or maybe "I hope those ropes don't break."

  • by internewt (640704) on Monday October 11, 2010 @02:39PM (#33862318) Journal

    This system might also be hackable, such that people can preserve their privacy and not be listened in on from hundreds of feet away.

    You simply have a microphone near your mouth, sample it, and repeat the sound out of a speaker with slight echoes with randomised delays. There must be something that could interfere with the process they use to "zoom in" on a particular sound source. Maybe if you can measure the distance to the listening device, it would be possible to manipulate the frequency of sounds you are making so as to create a standing wave or something that would cause the microphones to be overloaded or to hear nothing..... shit, maybe the tech that drives noise cancelling headphones could be used here? Who you are speaking to gets an earpiece with unedited sound piped to them, and speakers on your lapels kick out anti-sound so eavesdroppers hear nothing.

    So now in public, you just need to have strings of randomised flashing IR LEDs illuminating your face, so CCTV has a hard time capturing your image, and now something to mess with your voice so that The Man cannot listen in too! If you are thinking "paranoid fucker", I am thinking what the fuck business is it of people to listen in on me? And that's a rhetorical question: I don't need to be told to think of the children, etc..

  • by bytestorm (1296659) on Monday October 11, 2010 @02:49PM (#33862420)
    This is a cool application of a well used technique. http://en.wikipedia.org/wiki/Phased_array [wikipedia.org]
  • by Dammital (220641) on Tuesday October 12, 2010 @09:08AM (#33869210)
    I do some community theater work as a hobby - amateur stuff - and wonder if something like this could be used to track multiple actors on stage? Might be better than fitting them all with transmitters and lavaliers. Targeting would become the next problem, I guess.

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