| 摘要 |
A handsfree communication terminal apparatus includes a transit switch being controllable for passing signals from a microphone to a transmission interface, during a transmit mode of operation, and a receive switch being controllable for passing signals from the transmission interface to a loudspeaker, during a receive mode of operation. A transmit signal processing circuit followed by a converter circuit generate transmit binary signal assertions in response to syllable-like characteristics in the signals from the microphone. A receive signal processing circuit followed by a converter circuit generate receive binary signal assertions in response to syllable-like characteristics in the signals from the transmission interface. A controller includes transmit and receive bistable circuits, each being clock setable by the respective binary signal assertions and being jam reset in response to the opposite binary signal assertions. The controller also includes logic gates arranged to be responsive to the set and reset states of the bistable circuits for generating transmit and receive mode signals for controlling the respective switches to provide voice-switched operation of the apparatus.
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