A study on the sound scattering characteristics in random structure using Voronoi Tessellation

In room acoustic design, the use of acoustic diffusers is an effective method for achieving a uniform sound field and controlling reverberation. A common approach is to use periodic diffusers that control reflection directions based on the wavelength of sound. In this study, we explore the utilization of random and nonperiodic structures as acoustic diffusers, taking inspiration from the amorphous structures in nature. The irregularities in random structures are expected to enable the broad diffusion of a wide range of frequencies in various directions. We utilized Voronoi tessellation in both two and three dimensions to create 2D Voronoi diffusers with irregular aperture shapes and 3D Voronoi diffusers with irregular aperture shapes and slopes. Then, the acoustic diffusion characteristics of the 2D and 3D Voronoi diffusers were compared with a periodic-type structure through the finite element analysis and experiments. On the basis of these results, the irregularities in the openings and slopes of Voronoi diffusers broaden the scattering frequencies and enhance the scattering coefficients. This suggests that amorphous structures utilizing Voronoi tessellation can be effective as acoustic diffusers.