Measurement Of Random-incidence Scattering Coefficient Of Common Diffusers In A Reverberation Chamber

In the60-70th of last century, acousticians discovered that lateral sound diffusion contributes to subjective preference,and oval concert halls with lateral sound reflections can have good sound quality as classical’shoebox’concert halls. In the80-90th of last century, acousticians found out that diffusors used in auditoriums can increase sound uniformity, smoothen impulse response curve s and improve binaural dissimilarity and etc.Scientists like Vorlander have done lots of research works which demonstrate that, computer simulation based on geometrical acoustics may ignore sound diffraction and scattering. For getting a more accurate result,introduction of a scattering coefficient will be essential.As international standard for measuring Random-Incidence Scattering Coefficient has been issued, scholars have been doing measuring work to find how height and depth of a diffuser change influences the result.A scattering coefficient measurement system was set up according to the ISO17497-1in the reverberation chamber of State Key Laboratory of Subtropical Building Science in SCUT. The random-incidence scattering coefficients of seven MLS diffusers in the reverberation chamber were measured with the system, but with the edge uncovered. In this paper, these seven MLS diffusers are re-measured with their edges covered in disk, thus, the edge effect can be eliminated. Then, six more diffusers with random-sequence are measured to see whether MLS diffusers have their unique scattering property.The results demonstrate that, among all diffusers with the same height, MLS diffusers show the optimal frequency character of scattering, so they can be the best choice for interior design in a concert hall.