Evaluating the Applicability of Statistical Reverberation Theory in Rooms with Varying Compactness and Material distributions

Statistical reverberation theory is a foundational framework for describing sound in enclosures, yet it often fails in practical scenarios, especially in rooms with noncompact geometries or uneven material distributions.This study investigates its validity by examining the absorption and scattering coefficients that govern the build-up and decay of non-specular sound fields.Backwards integrated impulse responses, generated with an image source model and a SPPS model (I-SIMPA), are used to extract coefficients via exponential fittings.These reconstructed coefficients are then compared to the conventional mean areaweighted coefficients across scenarios with varying compactness and material distributions.Results indicate that the fit improves with increasing compactness and that in terms of the spatial distribution of material properties scenarios with opposing walls of differing material properties show the poorest agreement.The findings of this study highlight the need to assess room characteristics before applying statistical reverberation theory or use an acoustic prediction model that is (partly) reliant on it.