The effect of fluid–structural coupling on acoustical decays in a reverberation room in the high‐frequency range

Abstract

The effect of the fluid–structural coupling between the modes of a sound field and the modes of test panels placed in the sound field upon their decay behavior is investigated in the high‐frequency range. Quasitransient solutions of the average energies in the room and the panels are used to estimate the reverberation times in the room and to calculate the decay curves of a test panel. Experiments are conducted that verify these solutions. The estimated and measured results are in good agreement, which indicates that the average decay behavior of the room and panels can be analyzed in terms of the average modal parameters. The average modal parameters of the test panels and the reverberation room can be related to the Sabine absorption coefficient αSab of the panels. This result suggests an interpretation for the Sabine absorption coefficient of a modally reactive surface and provides a way to estimate this quantity using the statistical energy analysis (SEA) method. The dependence of the αSab upon the room properties, in which the panel is measured, is demonstrated both experimentally and analytically.