| 摘要 |
Extractor 11 segments input speech into overlapping periods of 30 msecs and supplies the segments to LPC analyzer 12 which produces parameters associated with each frame period of 20 msecs, and delivers signal 101 to K-quantization decoder 13. Quantized LPC parameter signal 104 passes to multiplexer 23 and to K-interpolator 14 which produces interpolated LPC parameters D during each frame period of 20 msec on the basis of two successively supplied LPC parameters. All parameters are supplied through K.???-converter 15 to temporary memory 16. Correlation between LPC filter impulse response and the input speech itself is calculated. The LPC parameters 103 for each frame period are read out in the reverse order and supply backward filtering processor 18, arithmetic circuit 24 and autocorrelation arithmetic circuit 25. Extractor 17 extracts each segment of frame period 20 msecs, in synchronism with extractor 11, and delivers the segments to processor 18 in the reverse time direction. <IMAGE> |
