| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmitter/receiver device with a secret talk function for automatically operating a secret talk function by incorporating a proximate sensor inside a transmitter/receiver without pressing any other button when executing the secret talk function. SOLUTION: In the transmitter/receiver device with the secret talk function such as telephone/interphone, a proximate sensor 13 is incorporated on the speaker side of a transmitter/receiver 10. When the transmitter/receiver gets apart from an ear, the proximate sensor 13 is turned off, a fault detecting circuit 16 detects an OFF signal, and a holding tone generating signal is outputted to a holding tone generating circuit 15 and holding tones are sent from the transmitter/receiver 10 so that a conversation on this side is inaudible.
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