High-order allpole modelling of the spectral envelope

The sinusoidal transform coder (STC) is a vocoding technique that has been evolving over the past few years which represents speech as a harmonic set of sinewaves and has demonstrated synthetic speech of good quality at rates from 2400 b/s to 4800 b/s. Previously, a cepstral model was used to code the sinewave amplitudes. This paper reports on a new approach that fits an allpole model to the sine-wave amplitudes and coding is done in terms of both scalar- and vector-quantization of the line spectral frequencies (LSFs). A new measure is developed to objectively quantify the quantizer design performance.<
>