A speech analysis system includes a codebook (230) that stores speech spectral parameters corresponding to a speech spectral hypothesis. The speech spectral hypothesis may be combined with a noise spectral hypothesis and the combined hypothesis compared to a sensed signal via a discriminant function...http://www.google.com/patents/US7478043?utm_source=gb-gplus-sharePatent US7478043 - Estimation of speech spectral parameters in the presence of noise
