Distribution of reflected sound levels in rooms with diffuse sound fields

Classical statistical theory predicts uniform reflected sound levels in rooms. In concert halls, Barron and Lee [1] observed decreasing reflected level with increasing source-receiver distance and developed a revised theory that predicts the average behaviour of sound levels more accurately. A diffuse sound field is taken as the reference condition for room acoustics and this paper will report on a model investigation testing whether this revised theory is also applicable in proportionate spaces with diffuse sound fields. The results presented are for measurements in two physical scale acoustic models, one having non-parallel geometry and the other with highly scattering surfaces. The spaces were also analysed using computer models. One interesting result concerned the scatter of measured sound levels and this is discussed with reference to previous work by Lubman [2] and Schroeder [3].