Effects of absorption placement on sound field of a rectangular room: A statistical approach

Abstract

Room resonances create dramatic fluctuations in the distribution of sound pressure throughout the listening region of a room. Previous studies indicate that the addition of sound absorbing material decreases room resonances and shifts its modal characteristics. The present study proposes an approach which qualifies the effects that the additional absorption in a listening room may have on the sound fields and the frequency responses. Finite element analysis was employed for modelling the low-frequency responses of a room. The study analyses frequency responses at various listening positions involving different amounts and different placement of sound absorbents on room surfaces by observing standard deviation for linearity across a chosen frequency range. Two-dimensional sound field plots at listening height were also used to examine the spatial changes of room resonances caused by the additional absorption. The present study applied a modified statistical approach to evaluate both the sound field and the frequency responses of a room. The results were then applied to re-evaluate the effects of the absorbers location on the listening region through the proposed approach.