Harmonic coding at 8 kbits/sec

In the last few years the interest in voice coding at medium to low bit rates has increased enormously. Some candidate techniques to code speech with telephone quality at these bit rates are Stochastic Coding, Multipulse and Harmonic Coding. For voiced sounds, Harmonic Codind is a very efficient and elegant technique [3][4]. In this paper we describe, for the first time, a version of a Harmonic Coder working at 8 Kbit/sec. In this version, the speech segments are divided into voiced and unvoiced. The voiced segments are treated by the Harmonic Model with the Variable-Frequency Synthesis (VFS) scheme [1]. The unvoiced segments are basically processed as in a Vocoder-Driven ATC [2]. In spite of the unfinished work, the present version achieves very good quality at about 8 Kbit/sec.