The effect of stationary diffusers in the measurement of sound absorption coefficients in a reverberation room: An experimental study

Abstract

It has not yet been established if stationary diffusers are effective in the measurement of the sound absorption coefficients of materials in a reverberation room. Although the results of such measurements may be strongly influenced by the use of diffusers, the conditions under which diffusing panels must be used and the number of such panels required have still not been ascertained exactly. In this paper we report the results of a series of measurements on different kinds of materials, performed in a reverberation room in both the presence and absence of diffusers, in order to establish the effect of diffusing elements on the absorption coefficient values. In some cases variations greater than 40 per cent were observed.