A method for predicting the reverberation time and decay curves of rectangular rooms with non-uniform absorption distribution using Statistical Energy Analysis

Laurence Wilmshurst , David Thompson

The subject of reverberation time in non-diffuse environments has been of considerable interest to acoustic engineers since the inception of room acoustics in the early twentieth century. Numerous prediction methods have been developed with the aim of accurately predicting the reverberation time of an enclosure under these circumstances, although a completely universal method has yet to be devised. This paper examines the decay processes in rooms where absorption is unevenly distributed throughout the enclosure, which is a common occurrence in practice and often leads to a non-diffuse sound field. In order to establish the nature of these decay processes, a seven-subsystem Statistical Energy Analysis model was developed, based initially on the axial, tangential and oblique mode groups and then extended to encompass the dimensions of formation. The damping loss factors were obtained analytically through the use of three independent methods as a means of verification and comparison. In addition to this, a method for deriving the coupling loss factors analytically from the scattering coefficients of the walls is also established. The validity of the predictions obtained using this method is then tested using various computer simulations and experimental data.

Mots clés: reverberation time; Statistical Energy Analysis; non-uniform absorption

Domaines: Acoustique [physics.class-ph]

Laurence Wilmshurst, David Thompson. A method for predicting the reverberation time and decay curves of rectangular rooms with non-uniform absorption distribution using Statistical Energy Analysis. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810686⟩