Visual assessments of the surface diffusion properties of concert halls

The diffusion of sound in concert halls has been recognized as significant in determining the acoustic quality of halls. The diffusion of sound in rooms is difficult to assess as are the diffusing properties of surfaces. The collective diffusing properties of the walls, floor and ceiling in a hall would seem to be almost impossible to assess objectively but such an assessment is needed for the design of concert halls. In this paper it is shown, indirectly, that visual assessments of the diffusion of concert hall interiors appears to be repeatable and reproducible to a degree which will allow halls to be designed to one of three broad classifications; “excellent”, “good” or “fair”.