| 摘要 |
PROBLEM TO BE SOLVED: To provide a hands-free telephone capable of sending transmission signals without sending unnatural sounds even while an echo canceller is executing the training. SOLUTION: The telephone comprises a second sending path composed of a microphone 11, an A/D converter 13 and an attenuator 18 separately from a main sending path composed of a microphone 1, an A/D converter 3, an echo canceller 5, and a sending digital amplifier 6. While the echo canceller executes the training, the second sending path is selected to transmit send signals not subjected to the training influence, and in other cases, the first sending path is selected to transmit send signals cleared of echoes removed by the echo canceller. COPYRIGHT: (C)2008,JPO&INPIT
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