A system for matching an input signal, including non-white noise and a patterned signal corrupted by the non-white noise, to a plurality of reference signals, the system including means for estimating noise features of the non-white noise (18) and for producing from the features at least one noise whitening filter (26, 28), filter means for filtering the input signal and the plurality of reference signals using the at least one noise whitening filter and producing a filtered input signal, having a white noise component (A) and a plurality of filtered reference signals (B) and pattern matching means generally robust to white noise for matching the filtered input signal to one of the filtered reference signals. In the system thus provided the at least one noise whitening filter is two noise whitening filters and the filter means operate in a feature domain.
SPEECH PATTERN MATCHING IN NON-WHITE NOISE