| 摘要 |
PURPOSE:To prevent that a listener continuously hears the abnormal sound and to identify the abnormal condition of the line by the listener by inserting the parameter-coded special sound signal when the omission of the receiving clock from the transmission line and the abnormality of the MODEM carrier signal turning off. etc., are detected. CONSTITUTION:An analog signal inputted through a transmitting line 5 to an analyzing circuit 1 is divided to a constant time unit by a sampling circuit 14, sampled simply and sent through a parameter analyzing circuit 15 and a parameter coding circuit 16 to a transmitting buffer 17. The information the clock signal accumulated to a transmitting buffer 17 synchronizes from a transmission line 6 including a MODEM, etc., and transferred through the transmission line 6 to a synthesizing circuit 2 of the receiving side device. When a line abnormality detecting circuit 23 of a synthesizing circuit 2' detects the condition of the omission of the receiving clock or a carrier signal turning-off, etc., a selector circuit 25 is changed over and the information from a parameter coding special sound generating circuit 24 is written in a receiving buffer 19. When the line condition is normal, the information from the transmission 6 is written into the receiving buffer 19.
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