Use of statistical energy analysis for the prediction of Sabine absorption coefficient of modally reactive panels

Abstract

Statistical energy analysis (SEA) is used to establish a relationship between the Sabine absorption coefficient of a modally reactive panel and the coupling of the panel with the sound field in a room. The acoustic-structural coupling is described by the coupling loss factors between the panel and the room. The application of the consistency relationship in SEA, which is based on the reciprocity principle, is shown to enable the coupling loss factors to be determined by directly exciting either the panel or the room. Each way of driving the acoustic-structural coupled system produces different values of the coupling loss factors and thus, of the absorption coefficient. The nature of discrepancy between the results of both ways of exciting the system is explained by using distributions of energy among structural modes of the panel and acoustic modes of the sound field, as well as distributions of modal coupling-loss factor among acoustic-structural coupled pairs of the modes. This paper provides an insight into the effect of the use of the consistency relationship on the prediction of the Sabine absorption coefficient of modally reactive panels by SEA.