Patent ID: 8538052

Claim:
A method of generating a probe noise signal for use in feedback cancellation in an acoustic system, the method comprising: capturing a digitized audio signal by storing consecutive values u(n) of the signal; deriving signal parameters from the captured digitized audio signal for controlling conversion of the captured digitized audio signal from time domain to frequency domain; determining a size parameter for controlling size of a series of magnitude values to be generated in the frequency domain; converting the captured digitized audio signal to the frequency domain U(k) by a transformation, whereby the series of magnitude values Mag[U(k)] and phase values Phase[U(k)], are obtained, wherein the number of samples in each transformation is based on a rate of change of the digitized audio signal; generating a series of artificial phase values Phase′[U(k)], which are substantially un-correlated to phase values Phase[U(k)] of the captured signal; and converting the series of corresponding magnitude values Mag[U(k)] and artificial phase values Phase′[U(k)] by an inverse transformation to a signal in the time domain thereby generating a digitized probe noise signal r(n) which is substantially un-correlated to the original audio signal u(n).