The Impact of Surface Scattering on Reverberation Time in Differently Shaped Spaces

Abstract

In terms of the overall diffusion sound field, the inherent diffusion state of the space and the scattering coefficient of indoor surfaces work jointly to diffuse sound energy. This study has investigated the impact of surface scattering on reverberation time in differently shaped spaces. First, 10 spaces with the same volume but different shapes were calculated using a computer simulation; Next, two typical spaces were selected to calculate 10 states, in which the volume was multiplied. The calculations results show that the impact of surface scattering on reverberation time in differently shaped spaces follows three laws: in a group of spaces with the same variation pattern, T20 varies with scattering coefficients at a similar rate. In a group of spaces with different variation patterns, there is a difference of more than 5% in the change rate of T20 with scattering coefficients; in imperfect diffusion spaces, decay curves vary in accordance with scattering coefficients. If the scattering coefficients are the same, T20 varies with spatial shapes; when the volume of rectangular spaces and trapezoidal space ranges from 3000 to 30,000 m3, the change rate of T20 is less than 5%. In the present study, spaces were classified by the position combination of shape surfaces. On this basis, we proposed and then graded the concept of “morphology diffusivity”.