NOISE REDUCTION DEVICE

• US 20100014683A1
• Filed: 07/13/2009
• Published: 01/21/2010
• Est. Priority Date: 07/15/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Maeda, Tsuyoshi, Kano, Hiroyuki, Asao, Yoshifumi, Higashida, Masaaki, Ezaki, Toshihiro
• Granted Patent: US 8,565,442 B2
• Time in Patent Office: Days
• US Class Current: 381/71.400
• CPC Class Codes: G10K 11/17854 the filter being an adaptive filter
• CPC Class Codes: G10K 11/17857 Geometric disposition, e.g. placement of microphones
• CPC Class Codes: G10K 11/17881 the reference signal being an acoustic signal, e.g. recorded with a microphone
• CPC Class Codes: G10K 2210/111 Directivity control or beam pattern
• CPC Class Codes: G10K 2210/1281 Aircraft, e.g. spacecraft, airplane or helicopter
• CPC Class Codes: G10K 2210/3221 Headrests, seats or the like, for personal ANC systems

Abstract

A noise reduction device including a noise detection microphone including a high-frequency noise detection microphone and a low-frequency noise detection microphone for respectively detecting a high-frequency noise and a low-frequency noise generated from a noise source; a noise control unit for generating a control sound signal for cancelling a noise detected by the noise detection microphone in a control center of control space; and a loudspeaker for outputting a control sound based on the control sound signal from the noise controlling unit. The high-frequency noise microphone is disposed in a vicinity of a head portion of a user in a state in which directivity in an opposite direction with respect to the control center is added, and the low-frequency noise detection microphone is disposed outside of a sound-insulating wall.

Claims

1. A noise reduction device comprising:

a noise detection unit including a high-frequency noise detection unit and a low-frequency noise detection unit for respectively detecting a high-frequency noise and a low-frequency noise generated from a noise source;

a noise controlling unit for generating a control sound signal for cancelling a noise detected by the noise detection unit in a control center of control space; and

a control sound outputting unit for outputting a control sound based on the control sound signal from the noise controlling unit,

wherein the high-frequency noise detection unit is disposed in a vicinity of the control center in a state in which directivity in an opposite direction with respect to the control center is added, and

the low-frequency noise detection unit is disposed in a position in which a sound emitted from the vicinity of the control center is attenuated to a predetermined level.

2. The noise reduction device of claim 1,

wherein the low-frequency noise detection unit is disposed in a predetermined distance from the control center.

3. The noise reduction device of claim 1,

wherein a sound-insulating wall is set in the control space, the low-frequency noise detection unit is disposed outside of the sound-insulating wall and the high-frequency noise detection unit is disposed inside the sound-insulating wall.

4. The noise reduction device of claim 1,

wherein the number of the high-frequency noise detection units to be placed is larger than the number of the low-frequency noise detection units.

5. The noise reduction device of claim 1,

wherein a seat disposed in a passenger vehicle is set in the control space.

6. The noise reduction device of claim 5,

wherein the control center is a position of a head portion of a passenger sitting in the seat.

7. The noise reduction device of claim 5 or 6,

wherein the low-frequency noise detection unit is disposed in a position at an equal distance from the control centers of two adjacent seats, and the low-frequency noise detection unit is shared by the two seats.