Patent ID: 7092529

Claim:
An adaptive noise canceling system for extracting a desired signal, comprising an adaptive noise cancellation filtering circuit for suppressing noise from a first input signal using a second input signal as a reference signal, and generating an output filtered signal representing the desired signal; and an adaptive noise cancellation controller for receiving the first and the second input signals and the output filtered signal, and generating an output control signal for controlling coefficients of at least one adaptive filter of the adaptive noise cancellation filtering circuit, comprising a silence detector unit for receiving signals respectively derived from the first input signal, the second input signal and the output filtered signal, detecting whether an acoustical signal is present in the input signals and the output filtered signal using the received signals, and generating a first output signal which indicates whether the acoustical signal is present; a signal detector unit for receiving signals respectively derived from the first input signal, the second input signal and the output filtered signal, detecting whether the desired signal is present in the input signals and the output filtered signal using the received signals, and generating a second output signal which indicates whether the desired signal is present; and an adaptive noise cancellation filter (ANCF) controller unit for receiving the first and the second output signals to determine the characteristic of the input signals, and generating the output control signal which represents an updated coefficient parameter for updating the coefficients of the at least one adaptive filter of the adaptive noise cancellation filtering circuit.