Vector quantization of pitch information in Mandarin speech

A method of quantizing the shape of pitch contour segments of Mandarin speech by using orthogonal polynomial representation and vector quantization techniques is proposed. Only a very limited number of representative pitch contour patterns of words can be found in Mandarin conversation; therefore, pitch information can be represented by the shape and the length of the pitch contour segment word by word instead of frame by frame. An average bit rate of 0.78 b/frame (34.67 b/s) for voiced sounds was achieved. The method is a variable-rate coding scheme with an average delay of 317 ms