Patent ID: 8031881

Claim:
An apparatus for processing sounds, including sounds from a user's mouth, comprising: a first microphone to produce a first output signal; a second microphone to produce a second output signal; a first directional filter adapted to receive the first output signal and produce a first directional output signal; a digital signal processor adapted to receive signals representative of the sounds from the user's mouth from at least one or more of the first and second microphones and to detect at least an average fundamental frequency of voice, or pitch output; a voice detection circuit adapted to receive the second output signal and the pitch output and to produce a voice detection trigger; a mismatch filter adapted to receive and process the second output signal, the voice detection trigger, and an error signal, wherein the error signal is a difference between the first output signal and an output of the mismatch filter; a second directional filter adapted to receive the mismatch output and produce a second directional output signal; and a first summing circuit adapted to receive the first directional output signal and the second directional output signal and to provide a summed directional output signal, wherein in use, at least the first microphone and the second microphone are in relatively constant spatial position with respect to the user's mouth.