Reverberated sound field modeling in coupled rooms using a diffusion equation

Sound modeling in coupled rooms has attracted considerable attention in the past, but accurate and operational models are still needed. In recent papers, a diffusion equation based model has been applied with success to unusual room shapes. This approach allows nonuniform repartition of energy, and is especially relevant in room acoustics for long rooms or complex spaces such as networks of rooms. The present work aims at validating the behavior of the diffusion model in the case of two acoustically coupled rooms separated by an open area. In this purpose, the time‐dependent diffusion equation is solved in three dimensions using a finite‐element solver. It allows one to predict both sound attenuation and reverberation time at any point of the coupled rooms. Parameters influencing the coupling, i.e., room relative sizes, aperture size and room absorption areas, are investigated. Results are then compared with the classical statistical theory of coupled rooms. Finally, a comparison with experimental data in two coupled classrooms is also provided.