| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a noise reduction device capable of obtaining a sufficient noise reduction effect while preventing howling by a simple configuration. <P>SOLUTION: A speaker unit comprises a speaker 1 held by a holding means without being attached to a baffle plate so as to add sound emitted from the front and back of the diaphragm, and a microphone 2 provided in a region where the sound emitted from the front and back of the diaphragm of the speaker 1 is added and offset. Noise reduction sound signals for which sound signals obtained by gathering the sound by the microphone 2 are phase-inverted are supplied to the speaker 1. <P>COPYRIGHT: (C)2009,JPO&INPIT |
