| 摘要 |
A hands-free speaking device is provided which is capable of removing ambient noise at the near side from the speech transmitting signal. The hands-free speaking device includes a speaker 51 for reproducing a received speech signal, a microphone 52 for outputting a speech transmitting signal, an echo canceler 55 for removing an echo 62 transmitted from the speaker to the microphone, and a voice detector 11 comprising a noise level monitoring circuit 2 for monitoring the level of the ambient noise 63 input to the microphone, a voice level monitoring circuit 3 for monitoring the level of voice signal 61 input to the microphone, and a comparator 4 for generating a signal for increasing the attenuation amount of an attenuator 10 to attenuate the transmitting speech signal when the noise level is higher than the voice level. Additional embodiments are discussed and include improvements which reduce the effects of ambient noise, howling, and line echo.
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