SOUND COLLECTION DEVICE

• US 20120014535A1
• Filed: 12/16/2009
• Published: 01/19/2012
• Est. Priority Date: 12/17/2008
• Status: Active Grant

• Current Assignee: Yamaha Corporation
• Original Assignee: Yamaha Corporation
• Inventors: Oouchi, Ryo, Suenaga, Yuichiro, Ukai, Satoshi, Hosoe, Seiichiro
• Granted Patent: US 9,294,833 B2
• Time in Patent Office: Days
• US Class Current: 381/92
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

The invention provides a sound collection device having little error in a desired directivity. The sound collection device includes a unidirectional microphone 12A, a unidirectional microphone 12B, and a unidirectional microphone 12C which are arranged on one plane. Each of the unidirectional microphones has the maximum sensitivity direction directed toward the inside of the arrangement. Each of the unidirectional microphones has a rear surface (direction of the minimum sensitivity) being open acoustically. Since the maximum sensitivity direction of each of the unidirectional microphones is directed toward the inside of the arrangement, the oscillation plane of each of the unidirectional microphones can be positioned substantially at the center of the arrangement. Thus, by adjusting the gain of the sound collected by the respective unidirectional microphones, the directivity can be freely formed on a flat plane with little error.

Claims

1. A sound collection device, comprising:

a plurality of unidirectional microphones;

a plurality of gain adjustment units which are configured to adjust gains of sounds collected by the respective microphones; and

an adder which is configured to add the gain-adjusted sounds to one another, wherein

the plurality of unidirectional microphones are arranged on one plane, and the maximum sensitivity direction of each of the unidirectional microphones is directed toward the inside of the arrangement.

2. The sound collection device according to claim 1, wherein another unidirectional microphone is provided at a position which differs from the one plane, the maximum sensitivity direction of the other unidirectional microphone being directed toward a direction opposite to a direction of the one plane.

3. The sound collection device according to claim 1, wherein another unidirectional microphone is provided at a position which differs from the one plane, the maximum sensitivity direction of the other unidirectional microphone being directed toward a direction of the one plane.

4. The sound collection device according to claim 1, wherein

the plurality of unidirectional microphones are arranged to constitute a polygon having vertices of the respective unidirectional microphones, and the maximum sensitivity direction of each of the unidirectional microphones is directed toward a line of the polygon or inside the polygon.

5. The sound collection device according to claim 4, wherein the plurality of unidirectional microphones are arranged so that sensitivity axes of the unidirectional microphones intersect at one point.

6. The sound collection device according to claim 5, wherein the plurality of unidirectional microphones are arranged on a circle around the one point as a center of the circle.

7. The sound collection device according to claim 1, wherein

the plurality of unidirectional microphones are arranged on a circle.

8. The sound collection device according to claim 7, wherein

the plurality of unidirectional microphones are arranged on the circle at regular intervals.