| 摘要 |
PURPOSE:To listen to desired sound without hindrance, by transmitting a sub- sound signal when a sound signal is biased to a main sound signal and transmitting the main sound signal when biased to the sub-sound signal through FM modulation at the reception of duplex sound signal. CONSTITUTION:In receiving duplex sound signals, a mode switching circuit 1 is changed over into ''main sound + sub-sound signal'' mode to obtain main and sub-sound signals from a multiplex demodulator 2 and outputted respectively from speakers 6 and 7. Further, the main and sub-sound signals are led to an FM modulator 8 via a switch circuit 9. The sound volume of the main and sub- sound signals is compared at a sound volume/sound quality balance control circuit 3, the result is given to a duplex sound signal switching circuit 10, and when the main sound signal is larger than the sub-sound signal, the sub-sound signal is transmitted to an FM modulator 8 and when the sub-sound signal is larger, the main sound signal is transmitted. Thus, the desired sound signals can be listened to without being interfered with the other sound signal. |
