| 摘要 |
PURPOSE:To reproduce sound at a high or low speed without changing the level, tone quality and length of sound and with no deterioration in sound quality, by making use of the periodical properties of the sound signal to multiply plural cycle waveforms by the weight coefficient for synthesization. CONSTITUTION:The sound signal given from a telephone is converted into a digital signal through an exchange channel 10 and stored in a magnetic disk device 15 via an interface circuit 13 and a buffer memory circuit 14. The circuit 14 collects the continuous sound signals for each block to secure the input/output of DMA mode to the device 15. The signals stored in the device 15 are read out to the circuit 14 and delivered continuously to a sound signal reproducing circuit 17 to be supplied to a pitch detecting circuit 18. Thus the pitch of the sound signal is detected, and meanwhile the sound signals are stored in a buffer memory circuit 19. An arithmetic circuit 20 reads a pair of sound signals out of the circuit 19 with a time interval equal to the pitch delivered from the circuit 18. These paired signals are multiplied by the weight coefficient corresponding to the time position for production another pair of signals. These paired signals are added together for production of a sound signal for reproduction. |
