摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an active silencing device, capable of effectively reducing noise which three-dimensionally spreads in a shape of a spherical wave, and to provide an air blower using the same. <P>SOLUTION: The active silencing device 51 includes: a plurality of ducts 52 and a sound wave generation unit 53 for silencing. The plurality of ducts 52 are hollow ducts including an entrance and exit, and the entrance faces a sound source of emission sound having three dimensional sound pressure distribution, and the emission sound is changed to a plane wave inside the duct. The sound wave generation unit 53 which is provided in each of the plurality of ducts 52, generates a sound wave in which a phase is opposite from the plane wave. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |