Title:
NOISE REDUCTION DEVICE
Document Type and Number:
WIPO Patent Application WO/2017/170321
Kind Code:
A1
Abstract:
A noise reduction device is provided with a plurality of noise microphones, a noise control unit, and a control speaker. The noise control unit generates a control sound signal for reducing the noise detected by the plurality of noise microphones at a control center of a control space. The number of sound microphones (420a) disposed at a distance less than a distance d shown in the relational expression d = d0 + t × v – λ/2 is less than the number of sound microphones (420b-420g) disposed at a distance greater than the distance d, where λ is the wavelength corresponding to a control frequency f of the plurality of noise microphones, d0 is the distance from the control center to the control speaker, t is the control delay time of the control speaker, and v is the sound velocity. The noise microphones (420b-420g) disposed in a position in which the distance from the control center is greater than the distance d are disposed such that the distances between mutually adjacent noise microphones are substantially equidistant.
Inventors:
ARAKI JUNJI
KUBOTA KENICHI
KUBOTA KENICHI
Application Number:
PCT/JP2017/012238
Publication Date:
October 05, 2017
Filing Date:
March 27, 2017
Export Citation:
Assignee:
PANASONIC IP MAN CO LTD (JP)
International Classes:
G10K11/178; B64D11/06
Foreign References:
| JP2009029405A | 2009-02-12 | |||
| JP2000322066A | 2000-11-24 | |||
| JP2009143392A | 2009-07-02 |
Other References:
See also references of EP 3438970A4
Attorney, Agent or Firm:
KAMATA Kenji et al. (JP)
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