Earlier quoted context omitted.
How does multi microphone filtering work? I guess they localize different sound sources by cross-correlation (to get the timings) and triangulation (based on the timings and the speed of sound)?
It's pretty neat! Here's how it works: When you record with a single microphone, you are going to pick up a great deal of background noise. This is because the mic will pic up the person speaking AND the background noise; there's no way to differentiate the two. With two microphones, we know the following: 1) we know where the microphones are 2) we have a general idea where the persons mouth is, because we know how t…
That does sound neat. Sounds like it could be combined with 3D localization to allow eavesdropping particular sounds sources even e.g. in large rooms with lots of people talking. Multipath/ghosting might make precise localization difficult though.