| 摘要 |
PURPOSE: To generate no click sound at the time of mode switching and keep secrecy at high level by generating a control signal, and delaying and transmitting a voice when a stationary period is detected. CONSTITUTION: A stationary period wherein the amplitude of a voice is less than a certain reference value throughout a given period is retrieved; when such a period is detected, the control signal is generated and the voice is delayed behind an initially give voice or the control signal and then transmitted. Namely, a transmitter 36 has a means which checks the output signal of a comparing means 21 for the given period, and this means generates the control signal, which is transmitted over a transmission channel and supplied to a processor 13. Consequently, a click noise accompanying mode switching is not generated and secret information can be protected completely. |
