US 2006/0188089 A1 · Reduction in acoustic coupling in communication systems and appliances using multiple microphones

Abstract

A system and method of digitally modeling and significantly reducing the direct coupling between a telephone appliance loudspeaker and microphone employs a handset microphone in a phone appliance, such as, for example, a speakerphone, as a reference channel along with the speakerphone microphone to reduce the direct coupling between the speakerphone loudspeaker and the speakerphone microphone. Using an analog adaptive echo cancellation scheme, the sensitivity and dynamic range of a telephone device microphone to speech from talkers in an enclosure but not from signals emitted by a telephone loudspeaker are enhanced. Nonlinear distortions produced by a telephone appliance loudspeaker are measured by a telephone appliance handset microphone and used in a feedback subsystem, e.g., network, to reduce nonlinear distortions in the telephone appliance loudspeaker and loudspeaker driving circuit.

Claims18

Dependent claims

An method of echo cancellation by reducing direct coupling of a speakerphone loudspeaker to a speakerphone microphone for a speakerphone having a handset, comprising:

adaptively measuring an acoustic path from the handset microphone to the speakerphone microphone by generating a signal from the handset microphone;
adaptively generating an analog acoustic echo canceling signal using the signal generated by the handset microphone;
generating a speakerphone microphone signal;
and
subtracting the analog acoustic echo canceling signal from the speakerphone microphone signal to modify the speakerphone output signal.

2 more elements

Dependencies are inferred from the claim text.

Reduction in acoustic coupling in communication systems and appliances using multiple microphones

Life of this patent

Reduction in acoustic coupling in communication systems and appliances using multiple microphones

Life of this patent

Abstract

Claims18