A 450 b.p.s. vocoder with natural-sounding speech
Y.M. Cheng, Douglas D. O’Shaughnessy · International Conference on Acoustics, Speech, and Signal Processing · 2002
An ARX model with glottal excitation is used to achieve an accurate and economical frequency compression of speech, and a short-term temporal decomposition is used to do temporal compression. Quantization properties of the new set of coefficients and of the side information are studied through vector quantization. Moreover, use is made of the sequential structure of the vectors produced by a short-term temporal decomposition to decrease further the coding bit rate. As an application of the above techniques, a 450-b/s vocoder with a 200-ms delay is described.>