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High-Tech Microphone Picks Voices From a Crowd
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..."
...is it 315 or 325? Sheesh.
...'tis easier to blame than to improve.
The Conversation
I once took an excursion to Reddit, and later HN. Unlimited up/down voting sucks when dealing with a hive-mind.
It occurs to me that if you store all 325 audio streams with accurate time-codes and the relative positions of the microphones you would be able to do this at any time later on the stored sound as well. You could probably get away with much fewer than 325 microphones at some cost in quality.
Yes. And that's already part of the system.
Maybe I should've read it then.
But I, like most Slashdotters, am so quick that I can just glance at a poorly written summary and instantly understand all that needs to be known about the topic. It's really a wonderful time-saver being so damn smart I don't even need to know the facts.
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This sounds like beamforming. Submarines do this. Works great.
How come you get terrified by an array of microphones with an impressive spatial detection capability? The thing is technically impressive, whether or not it "terrifies" a certain person is about perspective, and that person's tendency towards becoming terrified by mundane objects.
"Our two-party system is like a bowl of shit looking at itself in a mirror." - Lewis Black
This is a cool application of a well used technique. http://en.wikipedia.org/wiki/Phased_array
Just like Congress!
And, to be back on topic, referees.
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My father, would tell me stories when I was growing up about helping design a surveillance tool for ease-dropping on restaurant conversions that used the same principle. They had a map of the table layouts and you would place a pointer over the table you wanted to listen to. Mics hidden around the edge of the restaurant would capture the sound. This was back during the early 60's so they used a mechanical delay mechanism. Said it worked as well as if you had planted the mic at the table, plus you didn't have to worry about where they sat. Like many things, this is more powerful and versatile but hardly anything new.
Just in case anybody is confused, that is cool as shit. That's all.