| 摘要 |
PROBLEM TO BE SOLVED: To actively perform noise elimination control of noise in space where a noise source can be seen without being obstructed. SOLUTION: An active noise elimination controller is constituted of; wall surfaces which suppress the diffusing of noise; a sound wave reflecting board 2 which collects signal samples of noise to a focus; a noise detecting microphone 3 which is arranged at the focus of the sound wave reflecting board 2; a reverse phase speaker 4 which emits a sound wave whose phase is opposite to that of the noise, and whose sound pressure is the same as that of the noise outputted by the noise detecting microphone 3; and a sound emitting unit 5 which shapes the emission state of the sound wave which is emitted from the reverse phase speaker 4, and is characterized in that timing in which the sound wave emitted from a noise source 21 is made to coincide with timing in which the sound wave emitted from the reverse phase speaker 4, and whose phase is opposite to that of the noise, and whose sound pressure is the same as that of the noise join at the surface 22 and also an interference limit angle is given to angles of incidence to the surface 22 of wave bundles of both sound waves and also the size of the surface 22 is set to a size which does not exceeds a half of an interference limit wavelength. COPYRIGHT: (C)2006,JPO&NCIPI
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