AcousticsFirst.com/video
Using an array of ping pong balls to represent sound visually, this video simply demonstrates what occurs when sound strikes an acoustic diffuser's surface. First, you will see what happens when sound hits a flat reflective surface. The balls all bounce off at the same time and in the same direction. Then you will see what happens when sound hits a diffuser. You will immediately notice the energy of the wave of balls is scattered in all different directions and deflected at different times. This is the basic principle behind acoustic sound diffusion.