I am using an A2DP adapter (similar to NoiseHush N550) to speak and listen to my Nexus One (running 2.2-froyo). It works fine, except that I noticed that the Nexus One's microphone(s) are still active, picking up ambient noise, when what I really want is that the A2DP's microphone (which is closest to my mouth) will be the only one active.
Is there a way to tell Android to use only the Bluetooth microphone and mute the two built-in microphones?