| 摘要 |
PURPOSE:To obtain a high-quality sound transmission system, by making the sound outputting level of the system lower when the transmission reliability of a decoder inputting code sequence declines to such a degree that exceeds the capability of an error reducing means. CONSTITUTION:Sound signals inputted to a terminal 1 are encoded at an information source encoding section 2 and a forecasting residue is outputted to a terminal 2a and codes corresponding to encoding parameters are outputted to terminals 2b-2e. The outputs of the terminals 2b-2e are supplied to a framing circuit 4 through error correcting encoding circuits 3b-3e, respectively, and the output of the terminal 2a is directly supplied to the framing circuit 4. Then the outputs are transmitted as serial encoding sequences. A process opposite to the transmission side is performed on the output 9 of a receiver 8 by means of a decoder 16 and the processed output is outputted as sound signals from an output terminal 17. A receiving level signal 10 is outputted from the receiver 8 and, when the signal 10 is lower than a threshold, the level of the level of the sound output is made smaller through a comparator 11 and correction circuits 14a-14e.
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