I am [a biomedical engineer] considering a design for a robotic, autofocus stereo microphone pair to record bird calls. My concept is at a detailed "block diagram" phase. Before I go any further with my idea, I thought I would "ping" various tech sites to gather some input on existing work by others. I do not expect or desire any protected work produced by others. I believe my idea is relatively simple and can be accomplished with "off-the-shelf" technology.
Does this sound like anything already in use? Feel free to ask questions- I kept this posting brief on purpose.
A technique used to isolate a wild birdcall (or flying insect) is using a directional (e.g. parabolic) microphone pointed at the creature, and another omnidirectional mic recording ambient sound.
In postproduction the ambient sound is spectrally subtracted from the directional track to further isolate the sound of the wild creature.
Thanx for the quick reply, Timbre. I may incorporate a parabolic collector to give directional properties to what microphone I end up. Specifically, I am developing a autonomous robotic platform that will not only mount a microphone system but also position the microphones around X, Y, and Z axes to reduce background noise; non-specific sounds (airplanes, crickets, etc) while enhancing the target sound(s) desired.
In other words, I want to be able to record bird calls in the wild while I am NOT present. There are numerous locations where a particular bird can be anticipated. However, being there at the right time to record vocal activity is a challenge. Not to mention the effect human presence can have on bird behavior, no matter how quiet or motionless.
It is theoretically possible to isolate sounds in some plane in a stereo field temporally, but in the real world some sound from unwanted sources is reflected by surfaces which satisfies the same temporal constraints and is recorded with the wanted sound.
Have you contacted people in the "Yahoo Groups", Micbuilders and Nature Recordists ?
Thanx for the many and valuable replies. I have referred to the mentioned sources and then some. This is a challenge. I love it!