The Royal Albert Hall in London exhibits noticeable acoustic effects. So does your shower, although both very distinctly. Arguably, both have favorable acoustic properties, making them both pleasing spaces to listen to sing or play music within, despite their differences. But what does it all mean? Acoustics defines the properties of a room or building and determine the quality of sound produced within it. Acoustic diffusion is an important part of the effects of a room and its contents on the way it sounds, for better or worse.
Sound is a form of energy that travels in waves that reflect off or are absorbed by different materials to varying extents around the walls, furniture, and even the people in a given space. These reflections cause discrepancies that we experience as echoes. The term acoustic diffusion describes way sound energy is distributed around a particular environment. A perfectly diffused room is one where the acoustic properties are the same everywhere in that space. Few spaces are naturally perfect and need tweaking in order to achieve something approaching perfection.
What is an Acoustic Diffuser?
An acoustic diffuser mixes up reflected sound waves so they don't bounce around creating echoes. An audience serves as a type of diffuser where the people are what absorb sound waves. That is why the echoes will be greater in the cafeteria when there are only a few people at a PTA meeting than they are when the room is packed with students and teachers during an assembly.
If you add a spoonful of salt or sugar to a glass of water, it will diffuse from an area of high concentration to an area of low concentration until it is evenly distributed throughout. Stirring the water speeds up the process. An acoustic diffuser acts like a spoon by changing the concentration of sound waves in the room until they are evenly distributed.
Since it's rarely practical to move your audience around to get the best sound distribution, you call an expert to design one or more for you. These may take the form of furniture, sculptures, or three-dimensional wall-hangings.