GENERATION OF PROBE NOISE IN A FEEDBACK CANCELLATION SYSTEM

摘要

The invention regards a scheme for generating a probe noise signal to be used in an anti feedback system of an audio system. The audio system comprises e.g. a microphone for capturing an audio signal, an audio signal processor for adaptation of the audio signal and a receiver for generation of an audible signal. According to an embodiment of the invention, a noise signal is injected into the audio signal path between the microphone and the receiver and used for estimating acoustical feedback, the noise signal being generated by the following steps: converting a digitized audio signal to the frequency domain, in order to obtain a series of magnitude and phase values, changing the phase values such that the phase of the resulting signal becomes less correlated, preferably substantially un-correlated, to the original signal, converting the magnitude and phase back to a time domain signal using the changed phase values. The invention may e.g. be used in a hearing aid, a headset or a pair of headphones.