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AssigneeBridgestone Tire Company Limited
InventorsMasayasu Matsumoto, Kazuyoshi Iida, Yoshikazu Kondo, Keiichiro Mizuno, Sadao Nomoto, Noriaki Murayama, Kei Watanabe
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A device for controlling a propagation direction of noise which is preferably associated with a sound insulating wall to significantly improve its sound reducing effect of alleviating noise emitted from a noise source such as a railroad, highway and the like on which an electric car and automobiles run. The device comprises a hollow structural body composed of a plurality of elongate hollow passages superimposed one upon the other and spaced apart from each other. The passages are arranged in a propagation direction of noise emitted from the noise source and serve to refract and lag in phase the noise passed therethrough, thereby producing a sound reducing region located intermediate between a direct propagation sound and the refraction propagation sound.
A device for controlling a propagation direction of noise, comprising a hollow structural body composed of a plurality of elongate hollow passages superimposed one upon the other and spaced apart from each other, said passages being arranged in a propagation direction of noise emitted from a noise source, and adjacent passages located at least on a line perpendicular to said propagation direction and being different in length from each other, said noise emitted from said noise source passing through said adjacent passages of different length and refracted by all of said passages and lagged in phase with respect to direct propagation sound emitted from said noise source and passed over the upper edge of said hollow structural body to produce a sound region.
A device for controlling a propagation direction of noise as claimed in claim 10, wherein said plates are ridge-shaped plates.
Dependencies are inferred from the claim text.