Patent ID: 8577057

Claim:
A method of operating a microphone system, comprising the steps of: providing first and second microphones associated with a same human speaker; receiving an analog first signal from the first microphone; receiving an analog second signal from the second microphone; converting the analog first signal into a digital first signal; converting the analog second signal into a digital second signal; performing digital noise cancellation on the digital second signal dependent upon the digital first signal to generate a noise canceled digital second signal, the digital noise cancellation being performed by digital circuitry; inputting the noise canceled digital second signal into an intercom system; sensing a low power condition of the microphone system and/or a failure of the digital circuitry; and in response to the sensing step, inputting an analog-based intercom signal into the intercom system, the analog-based intercom signal being dependent on the analog second signal and substantially independent of the analog first signal, the analog-based intercom signal being input into the intercom system without having performed noise cancellation on the analog-based intercom signal, wherein, upon startup of the microphone system, the analog-based intercom signal is inputted into the intercom system until the digital circuitry is operable.