| 摘要 |
<P>PROBLEM TO BE SOLVED: To make noise outputted by an acoustic echo canceler to natural noise. <P>SOLUTION: This conference telephone system has the acoustic echo cancelers 104, 105 which cancel echos to voice signals outputted by a microphone 103 using the voice signal from a remote speaker as a reference signal, a near end environmental noise detection part 106 which defines power by adding a first threshold to transmission power minimized from the minimum transmission power by a plurality of first sections as second threshold power in a second section and detects a signal section of transmission power smaller than transmission power by averaging the minimum transmission power by each first section smaller than the second threshold power in the second section, a near end noise storage part 107 which stores signals of the detection part from an input point and has a plurality of output points and a near end noise processing part 108 which adds signals of the plurality of output points of the near end noise storage part 107 to outputs of the acoustic echo canceler. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
