Abstract
The sound insulating mechanisms of sandwich panels which consists of two surface sheets with another layer inserted bed between them, are classified into three groups by the acoustical properties of the inserted material, as follows 1 Rigid Type, 2 Elastic Type, 3 Resitivity Type. These three mechanisms are simulated by electrical curcuits and then theoretically their brequency characteristics of sound transmission loss are obtained. Also the sound transmission loss of 12 kinds of practical sandwich panel has been measured at our laboratory using international method recommended by I.S.O. The theoretical and experimental results are corefully compared in order to obtain a practical method of designing sandwich panel which hrs desired frequency characteristic of T.L.
