| 摘要 |
PURPOSE:To obtain a decoder from which no unpleasant noise attended with a stepwise change in a DC component is outputted by outputting a non-voice signal instead with the DC component eliminated therefrom when a fault state that a data series to the decoder cannot be decoded into a voice signal before coding takes place. CONSTITUTION:A fault state detection circuit 102 always monitors a data series 1a and outputs a fault state signal if to a changeover circuit 104 when any fault is detected. The changeover circuit 104 receiving the fault signal selects a digital non-voice signal 1e generated from a non-voice signal generator 103 as a decoder output signal 1b. When the data series 1a is normal, the changeover circuit 104 selects a digital voice signal 1d decoded by a decoder 101 as the decoder output signal lb. |
