| 摘要 |
PROBLEM TO BE SOLVED: To provide a versatile technique for supporting directivity control of sound emitting apparatuses so that sound pressure is sufficiently strong inside service areas and sound is sufficiently attenuated outside the service areas, and for dispensing with excessive calculation time. SOLUTION: When the sound emitting apparatus radiates sound waves toward a rectangular service area, a target area for the directivity control is set while coinciding with the service area. For sound waves radiated from the sound emitting apparatus, where the directivity is controlled so that the sound waves on a wavefront toward the target area are radiated, a sound pressure gradient in a direction from the inside to the outside strides over a side for dividing the inside and outside of the service area is calculated for each side. When the attenuation of the sound pressure is too sharp, the target area is widened to the outside. When the attenuation of the sound pressure is too gentle, correction for narrowing the target area to the inside is performed. The target area after the correction is used to control directivity again. COPYRIGHT: (C)2010,JPO&INPIT
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