Band-widened harmonic vocoder at 2 to 4 kbps

For speech coding at a bit rate below 4 kbps, the attention has been concentrated on sinusoidal-based vocoders during the past decade. Several models such as multiband excitation (MBE) have been proposed to synthesize high quality speech while removing the “buzzy” quality often produced because of over strong periodicity. This paper proposes a new model for voiced speech coding at very low bit rates, referred to as band-widened harmonic coding (BWH). This model was demonstrated to be able to win some advantages over existing ones in both quality and complexity. A comparison between the BWH and the MBE will be given in this paper