×

Adaptive noise canceller

  • US 5,473,702 A
  • Filed: 06/02/1993
  • Issued: 12/05/1995
  • Est. Priority Date: 06/03/1992
  • Status: Expired due to Term
First Claim
Patent Images

1. A method of using a secondary audio signal to cancel noise in a primary audio signal, comprising the steps of:

  • filtering said secondary audio signal according to a set of coefficients, thereby generating an estimated noise signal;

    subtracting said estimated noise signal from said primary audio signal to generate an error signal for use as an audio output signal;

    monitoring a power level of said error signal to generate a control signal;

    when said power level exceeds a threshold which is updated according to said power level, making said control signal active to hold said coefficients constant; and

    when said power level does not exceed said threshold, making said control signal inactive to update said coefficients according to said error signal.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×