Microphone support device for sound source detection

Abstract

A ring-shaped frame (2), a plurality of fixed arm parts (4) protruding toward the inside of the frame (2), and a plurality of movable arm parts (8) longer than the fixed arm part (4) and detachable ) and a plurality of microphones (14). By accommodating a plurality of movable arms (8) radially inside the frame (2), a small-sized microphone array as shown in FIG. 8(A) is constructed. On the other hand, by radially extending a plurality of movable arms (8) outside the frame (2), a large-sized microphone array as shown in FIG. 8(B) is constructed. In this way, when constructing a circular two-dimensional microphone array, its size can be easily changed, and it is possible to cope with wide-band sound detection.

Description

technical field [0001] The invention relates to a microphone support device for sound source detection used to construct a two-dimensional microphone array in a sound source detection system. Background technique [0002] The sound source detection system using the beamforming theory is a technology that uses a plurality of microphones to form a microphone array, and realizes sensitive directivity by operating and synthesizing the amplitude and phase input to each microphone, thereby extracting only the direction of the target. sound. Furthermore, as a microphone array used in such a sound source detection system, for example, the microphone arrays described in Patent Document 1 and Patent Document 2 have been proposed. [0003] In the microphone arrays described in these patent documents 1 and 2, a plurality of microphones are respectively arranged at predetermined intervals on a plurality of radial lines. The case of pointing to the center of the concentric circle. As a...

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Problems solved by technology

On the other hand, if you try to widen the distance between the microphones to ensure a sufficient phase difference, there will be a problem that the phase will exceed 360 degrees in the high-frequency region instead, resulting in an excessively large difference, which will increase the sidelobe level.

[0005] In other words, when the microphone arrays represented by the above-mentioned Patent Documents 1 and 2 are applied to, for example, the sound detection system of an electric powertrain unit of an automobile, broadband noise of about several Hz to several KHz will be generated in the vehicle, so a single Microphone arrays of this size cannot cope with sound detection of these broadband noises

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