| 摘要 |
PROBLEM TO BE SOLVED: To provide a line array unit which improved in directivity control for high frequency bandwidth and low frequency bandwidth, while holding down the cost. SOLUTION: Ten inner microphone units 353 are disposed at an equal distance (d). On the other hand, microphone units 353 located outside from the above-mentioned section are disposed at a distance between units extended by an integer multiple (d×integer), based on the number of units. Namely, the inner ten units are disposed at the distance (d), and outer units are disposed by extending the distance between units to 2d, 3d and 4d. According to the arrangement, directivity control characteristics for low frequency bandwidth is secured by extending an array width L even the number of microphones is small so as to hold down the cost, while directivity control characteristics for high frequency bandwidth is secured without generating another sound pickup beam since many microphone units are disposed at an equal interval by distance (d) in a dense array of the inner array. COPYRIGHT: (C)2007,JPO&INPIT
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