US 8,577,057 B2 · Digital dual microphone module with intelligent cross fading

Abstract

A method of operating a microphone system includes providing first and second microphones associated with a same human speaker. An analog ambient noise signal is received from the first microphone. An analog speech signal is received from the second microphone. The analog ambient noise signal is converted into a digital ambient noise signal. The analog speech signal is converted into a digital speech signal. Digital noise cancellation is performed on the digital speech signal dependent upon the digital ambient noise signal. The digital noise cancellation is performed by digital circuitry. The noise canceled digital speech signal is inputted into an intercom system. A low power condition of the microphone system and/or a failure of the digital circuitry is sensed. In response to the sensing step, an analog-based intercom signal is inputted into the intercom system. The analog-based intercom signal is dependent on the analog speech signal and substantially independent of the analog ambient noise signal. The analog-based intercom signal is inputted into the intercom system without noise cancellation having been performed on the analog-based intercom signal.

Claims19

Dependent claims

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.

7 more elements

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 ambient noise signal from the first microphone;
receiving an analog speech signal from the second microphone;
converting the analog ambient noise signal into a digital ambient noise signal;
converting the analog speech signal into a digital speech signal;
performing digital noise cancellation on the digital speech signal dependent upon the digital ambient noise signal to generate a noise canceled digital speech signal, the digital noise cancellation being performed by digital circuitry;
inputting the noise canceled digital speech signal into an intercom system;
sensing a low power condition of the microphone system and/or a failure of the digital circuitry;
in response to the sensing step, ascertaining that a volume level of the noise canceled digital speech signal is below a threshold level, the ascertaining step including detecting a strength or magnitude of the noise canceled digital speech signal;
and
in response to the ascertaining step:
performing cross-fading from the noise canceled digital speech signal to an analog-based signal that is dependent on the analog speech signal and substantially independent of the analog ambient noise signal, the cross-fading producing a cross-faded intercom signal;
and
inputting the cross-faded intercom signal into the intercom system.

11 more elements

A method of operating a microphone system, comprising the steps of:

providing first and second microphones associated with a same human speaker;
upon startup of the microphone system:
receiving an analog ambient noise signal from the first microphone;
receiving an analog speech signal from the second microphone;
inputting an analog-based intercom signal into an intercom system, the analog-based intercom signal being dependent on the analog speech signal and substantially independent of the analog ambient noise signal, the analog-based intercom signal being input into the intercom system without having performed noise cancellation on the analog-based intercom signal;
and
initializing a digital circuitry;
after the startup has been completed and the digital circuitry has been initialized:
converting the analog ambient noise signal into a digital ambient noise signal;
converting the analog speech signal into a digital speech signal;
performing digital noise cancellation on the digital speech signal dependent upon the digital ambient noise signal to generate a noise canceled digital speech signal, the digital noise cancellation being performed by the digital circuitry;
and
inputting the noise canceled digital speech signal into the intercom system.

10 more elements

Dependencies are inferred from the claim text.

Digital dual microphone module with intelligent cross fading

Life of this patent

Digital dual microphone module with intelligent cross fading

Life of this patent

Abstract

Claims19