| 摘要 |
PURPOSE:To eliminate the phase disorder of an acoustic signal generated by DPCM (differential pulse code modulation) at a concatenation point and to obtain a playback signal which provides good sensation of heating without any noise by marking data so that bracketing points of respective blocks which sections the acoustic signal are in phase when the acoustic signal is written in a memory. CONSTITUTION:A zero-cross detecting circuit 12 which inputs a peak detection signal (b) outputs a marking command signal (c) to a marking circuit 13 simultaneously with the input of the peak signal. When time-axis compression is carried out during a read of data from an RAM7, marks added to the encoded data are addressed to skip every other block of the data which is read out block by block. On the other hand, when time-axis expansion is performed, a bracketing point of the signal for every block which is obtained in time-axis conversion is given at the time of the peak of the acoustic signal and in phase. Therefore, acoustic signals in respective blocks are concatenated in phase and the signal reproduced by decoding has no large phase shift. |
