| 摘要 |
PURPOSE:To reduce a sense of incompatibility at the insertion of noise by inserting a pseudo noise signal whose signal level is attenuated gradually with the elapsed time to a receiving output channel at the silence state not assigned to a relay channel. CONSTITUTION:When a digital sound insertion DSI signal 5 is inputted to a receiving assignment control circuit 6, the circuit 6 transmits a receiving relay channel signal 61 to a signal selecting circuit 9 and transmits a receiving assignment signal 62 to an assignment missing detection circuit 7. The circuit 7 transmits an assignment missing channel signal 71 to the circuit 9 in response to a receiving output channel not assigned with a relay channel and also a noise insertion start signal 72 to a noise level control cirlcuit 11. The circuit 11 gives a noise level control signal 12 to a noise signal generator 8 by receiving the signal 72 and a noise signal 81 is transmitted from the generator 8 to the circuit 9. Thus, the pseudo noise signal whose signal level is attenuated gradually with the elapsed time is inserted to the receiving output channel with silence state and outputted. |
