| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a sound distribution device that has a uniform sound range in the longitudinal direction and prevents rainwater, dust, worm, angleworm or the like from entry to reduce wiring work hours as a secondary purpose. Ž<P>SOLUTION: The sound distribution device includes a reflection wall member made of a material having high-sound impedance and a sound source arranged at one end of a sound waveguide with multiple sound holes through predetermined points from the inside to the outside space. The other end of the sound waveguide is blocked. The sound holes are positioned at the peak of a standing wave corresponding to the length of the sound waveguide and positioned at the peak of odd-order harmonics of the standing wave on a bus line of the sound waveguide. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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