| 摘要 |
PURPOSE:To achieve the more accurate transmission of a signal tone, by separating an audible signal tone into audio, encoding the audible signal tone in a low speed directly, and performing audio analysis in the required speed after A/D converter. CONSTITUTION:After an audible signal tone is converted into a digital signal at an A/D converter 1, interleaving is made at a signal interleaving circuit 2. The output of the circuit 2 is formed into a frame format for audible tone at a frame forming device 4 and transmitted to a transmission line. At the reception side, an accurate original signal is reproduced by making reverse operation. On the other hand, the audio signal is introduced to an audio analyzer 3 after A/D conversion 1. The switching of the circuit 2 and the analyzer 3 is made by using the off-hook of a telephone set. Thus, since the audible signal tone can be transmitted and reproduced after being converted to frames without passing through the audio analyzer and synthesizer, the signal tone can be transmitted accurately. |
