Patent ID: 8885836

Claim:
A method for decorrelating an input audio signal that comprises: filtering the input audio signal according to a first impulse response in a first frequency subband to generate a first subband signal that represents the input audio signal in the first frequency subband with a frequency-dependent change in phase having a bimodal distribution in frequency with peaks substantially equal to positive and negative ninety-degrees, and according to a second impulse response in a second frequency subband to generate a second subband signal that represents the input audio signal in the second frequency subband with a frequency-dependent delay, wherein: the second impulse response is not equal to the first impulse response, the second frequency subband includes frequencies that are higher than frequencies included in the first frequency subband, the first frequency subband includes frequencies that are lower than frequencies included in the second frequency subband; the first impulse response represents a banded phase-flip filter in cascade with a low-pass filter; and the second impulse response represents a frequency-dependent delay in cascade with a high-pass filter; and generating an output signal that represents a combination of the first subband signal and the second subband signal, and has a measure of mathematical correlation with the input audio signal that varies over frequency and has averages across perceptual subbands that are closer to zero than averages across narrower bandwidths.