Abstract
Double leaf sound insulating wall is widely applied to cabins of air plane, high speed train and cars,because transmission loss is larger nevertheless the weight is light. But transmission loss of double leaf wall is decreased at the resonances of panels and air space between them. We experimented the improvement of transmission loss by using the perforated panel set in the air space and the dynamic vibration absorber set on the sound radiated surface of the wall. We found that both devices worked well even if we set perforated panel and dynamic vibration absorber at once, and that frequency region in which transmission loss was increased became wider. And we found that computated results which were derived by using FEM for analysis as vibro-acoustic problems were consistent with experimental results.
