Experimental investigation on sound absorption characteristics of microperforated panel in diffuse fields

Measurements of the absorption characteristics of Microperforated Panel Absorber (MPA) have been carried out in the standing wave tube and reverberation Chamber.Also Measurements of mixed MPP construction were made.The purpose is to compare and to find the relation of normal and random incidence.The results of calculation and measurement are presented,and some factors which affect the characteristics of MPA are given in the paper.Finally some suggestions for further study are proposed.