Abstract: An adaptive filter for echo cancellation includes a segmented sparse transversal filter having an input, the filter having an adjustable length, adjustable lengths for the segments and adjustable tap weights. The adaptive filter further includes an adaptive tap weight control mechanism providing a tap weight vector including tap weights and a tap weight vector length to the taps of the transversal filter, the adaptive tap weight control mechanism setting the tap weights and the tap weight vector length in response to comparison of estimated truncation error to a target truncation value and in response to a magnitude of integrated cross correlation coefficients between a reference signal and an error signal from the adaptive filter.

Abstract: The digitally sampled data is split into a plurality of subbands each covering a different frequency range. The subbands are each individually expanded to normalize the energy in each band and the subbands are converted by FFT to the frequency domain and the magnitude and phase portions are processed by different techniques based on psychoacoustic principles. Magnitude data are processed by tree structured vector processing to develop code books for each subband which are unique to each song. Phase data are uniformly quantized with dynamic bit allocation used to increase resolution on transient passages.