Method For Quantifying An Ultra Low-Rate Speech Coder

Method of coding and decoding speech for voice communications using a vocoder with very low bit rate comprising an analysis part for the coding and the transmission of the parameters of the speech signal, such as the voicing information per sub-band, the pitch, the gains, the LSF spectral parameters and a synthesis part for the reception and the decoding of the parameters transmitted and the reconstruction of the speech signal comprising at least the following steps: grouping together the voicing parameters, pitch, gains, LSF coefficients over N consecutive frames to form a superframe, performing a vector quantization of the voicing information in the course of each superframe by formulating a classification using the information on the chaining in terms of voicing existing over 2 consecutive elementary frames, the voicing information makes it possible specifically to identify classes of sounds for which the allocation of the bit rate and the associated dictionaries will be optimized, coding the pitch, the gains and the LSF coefficients by using the classification obtained previously.