Study on Verification of sound refraction in porous material and investigation of insertion effect of porous material into light double leaf wall

在声从空气中斜入射到多孔介质中的情况下，由于声在多孔介质中的速度比在空气中的速度低，因此已经猜测声折射现象。本文以声折射为主要研究对象，通过空气中声斜入射到典型多孔材料玻璃棉中的声学实验，验证了声折射现象。此外，建立了玻璃棉插入对轻质双叶墙体隔声效果的定量把握方法。结果表明，插入效应与声在双层叶壁多孔材料中沿声折射路径沿着传播长度的衰减量相对应。

In the case of oblique sound incidence into porous media from the air, phenomenon of sound refraction has been guessed because sound velocity is lower in the porous media than that in the air. Main subject of this study was sound refraction, then the phenomenon wad verified by acoustical experiment on the oblique sound incidence into glass wool of typical porous material from the air. Moreover, establishment of quantitative grasping method of insertion effect of glass wool on the sound insulation of lightweight double leaf wall. It was confirmed that the insertion effects corresponded to the sound attenuation according to propagation length along the sound refracted path in porous material in double leaf wall.