Statistical absorption coefficient of microperforated absorbers

Special attention is paid to the characteristics of microperforated panel absorbers (MPA) in a so-called random or diffuse sound field. Preliminary analysis based on the theory of "normal model" are given. Measurements for different kinds of MPA in the reveberation chamber have been carried out and useful results have been obtained. For the theoretical predictionsʹ PC-software has been developed. The further stuides in the near future are proposed. PACS numbers: 43.10, 43.50, 43.55