September 22-25, 1997
This paper presents some improvements to the mixed Harmonic and Stochastic eXcitation (HSX) algorithm in the context of low bit rate speech coding (around 2.4 kbit/s). The dominant issue is the modeling of the excitation signal in order to improve the quality of the synthesized speech signal without increasing neither the bit rate nor the complexity. The pitch tracking algorithm is revised in order to increase the robustness and to reduce the complexity. The voicing analysis algorithm is also refined. Informal listening of the synthesized speech at 2.4 kbitls shows a significant improvement.
Bibliographic reference. Matmti, Ridha / Jelinek, Milan / Adoul, Jean-Pierre (1997): "Low bit rate speech coding using an improved HSX model", In EUROSPEECH-1997, 1287-1290.