Patent ID: 7761106

Claim:
A system to support background noise reduction in a communication device, comprising: a first microphone located at a first location and operable to collect primarily a user's voice signal; a second microphone located at a second location and operable to collect a primarily background signal other than the user's voice signal; and a voice coder operable to: receive signals from both the first microphone and the second microphone; and generate an enhanced signal with reduced noise and improved signal-to-noise ratio (SNR); a noise reduction component associated with the voice coder operable to compensate or remove background noise from the first microphone signal using the background noise signal from the second microphone; the noise reduction component further comprises: a synchronizer circuit operable to synchronize the signals from the first microphone and the second microphone when there is a delay that is not otherwise compensated for; a continuous time quadrant modulation circuit operable to reduce background noise by subtracting the primarily background noise signal from the second microphone from the background noise component of the composite signal from the first microphone via analog signal processing; a discrete time circuit operable to perform: slowing or controllably delaying the progress or propagation of the signal from the first microphone; reducing background noise by subtracting the signal from the second microphone from the background noise component of the composite signal from the first microphone via digital signal processing.