The paper describes an investigation of some problems of sound diffusion in rooms, with particular reference to small sound and television studios. The experimental work shows that it is possible to measure the degree of diffusion in a room by fairly simple practical techniques. Quantities based on the frequency variation of reverberation time and double reverberation decay constants are the most promising for use in small broadcasting studios.It is also shown that uniform distribution of absorption can be as effective as other means of attaining conditions of good diffusion. Rectangular diffusers are particularly effective in improving conditions where the distribution of absorption is poor.