| 摘要 |
PURPOSE:To prevent an abnormal sound from being generated, by holding a step width of before an error is generated, while its error is generated, when an error of a delta modulating signal is generated. CONSTITUTION:A delta modulating signal 9 turns off a switch 24 and 25 provided in a demodulator use step width control circuit 10 consisting of a shift register 15, a smoothing circuit 19, etc. by detecting a random error in case a step width is comparatively large or a burst error extending over several bits, and impressing its detecting signal to a terminal 23. In case an error signal is not generated, both the switch 24 and 25 become on, and a step width of a size corresponding to a state of usual delta modulating signal train is inputted to an integration circuit 13, but in case an error is generated, the switch 24 and 25 are turned off, and the integration circuit 13 holds a decoding signal level of immediately before the error is generated, and prevents generation of an abnormal sound based on the error. |
