| 摘要 |
PROBLEM TO BE SOLVED: To provide a sound shielding structure body which is light in weight and has a superior sound shielding characteristic. SOLUTION: The sound shielding structure body is made of a lump shaped body having a surface which is arranged facing toward the incident direction of sound waves while the body is used. At least equal to one or more number of holes, which go through the body along the direction same as the direction of the incident sound waves, are made on the surface. The thickness of the lump shaped body along the through-holes is set within (λ/4)±10mm (whereλis the wavelength of the sound waves), the diameter of the holes is set within the range of 1 to 10mm and the percentage of the sum of the cross sectional areas of the holes along the diameter direction to the total area of the surface is set to a range of 1 to 20%. COPYRIGHT: (C)2005,JPO&NCIPI
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