Being the acoustic scatterer and the acoustic

摘要

PROBLEM TO BE SOLVED: To provide a sound scatterer which can obtain better sound scattering characteristics in a wider frequency band without degrading the space efficiency. ;SOLUTION: The cross sectional shape of a sound scatterer consists of a base portion constituted of seven isosceles triangles and a surface portion arranged on an upper surface of the base portion. The cross sectional shape of the base portion is obtained by providing an isosceles triangle 30a having a base equal to the length of a rear surface of the sound scatterer, then superposing, on oblique lines of the isosceles triangle 30a, isosceles triangles 30b each having a base equal to the oblique lines of the triangle 30a, and further superposing, on oblique lines of the isosceles triangles 30b, isosceles triangles 30c each having a base equal to the oblique lines of each triangle 30b. That is, the base portion is formed into three-tiered isosceles triangles. The surface portion which functions to scatter sound waves in the sound scatterer is formed into circular arcs connecting between three vertexes of the isosceles triangles on the uppermost tier, i.e., the four isosceles triangles 30c.;COPYRIGHT: (C)2000,JPO