Patent ID: 6925435

Claim:
A speech encoder for encoding a speech signal having a spectrum, said spectrum being divided into a plurality of sub-bands, said speech encoder comprising: a background noise suppression element configured to pre-process said speech signal and to generate a background noise reduced speech signal; and a linear prediction (LP)-based synthesis-by-analysis coder coupled to said background noise suppression element and configured to apply an LP-based coding process to said background noise reduced speech signal, said LP-based synthesis-by-analysis coder including an error weighting filter for shaping a spectrum of an error signal; wherein said background noise suppression element is further configured to perform a first background noise reduction operation to emphasize harmonic frequencies of said speech signal in each sub-band of said plurality of sub-bands and to reduce background noise between harmonic peaks of said harmonic frequencies to generate said background noise reduced speech signal; wherein said background noise suppression element is further configured to determine whether said speech signal is a voiced signal or an unvoiced signal, and wherein said background noise suppression element performs said first background noise reduction operation if said speech signal is said voiced signal, and wherein said background noise suppression element performs a second background noise reduction operation if said speech signal is said unvoiced signal; and wherein said LP-based synthesis-by-analysis coder applies said LP-based coding process to said background noise reduced speech signal whether voiced signal or unvoiced signal.