Influence of direct sound on the fluctuations of the room spectral response

This is the authors' abstract. We don't add key points for this paper.

Fluctuations of the room spectral response are theoretically studied taking direct sound into consideration. An exact, simple, analytical formula is derived which describes the dependence of the intensity fluctuations upon the direct-to-reverberant acoustic energy ratio. In much the same way an exact integral representation is obtained for the fluctuations of the sound intensity level (measured in decibels). The derived relations are useful for determining reverberation distances.