| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce only an unnecessary noise to solve a conventional problem that, when all surrounding sounds are canceled as a noise at the time of a noise reduction, a voice from another operator is also removed. <P>SOLUTION: A noise reduction device 20 comprises: a flash memory for storing a noise frequency which was measured in the past for a noise generated by a machine as a noise source; a sound-collecting circuit for collecting surrounding sounds; and a noise treatment part including a filter circuit for attenuating a frequency component corresponding to the noise frequency from the collected surrounding sounds. <P>COPYRIGHT: (C)2012,JPO&INPIT |
