Acoustic field perfectly diffused (diffusive)

Professional Definition

A diffuse acoustic field in which at every point, the quantity characterizing acoustic vibrations has the same amplitude, and all directions of wave propagation are equally probable.

This is a theoretical model assuming complete isotropy (independence from direction) and homogeneity of the acoustic field. Under laboratory conditions, a diffuse field is generated in special reverberation chambers with hard, non-parallel walls, often using suspended scattering devices. This is essential for reliable measurement of the reverberation sound absorption coefficient ($ \alpha $).

Acoustics in Simple Words

Think of a dense fog on a milky-white day. Wherever you look, the brightness is the same. You cannot pinpoint exactly where the sun is because the light has been so strongly scattered by water molecules that it reaches your eyes from every possible direction with the same intensity. Diffuse field is just such an “acoustic fog.” No matter where you stand in the room and which direction you turn your head – the noise level will be identical, and locating the source of the sound by hearing will become impossible.

Summary

An ideally diffuse acoustic field is a state of energetic equilibrium of sound waves. Although difficult to achieve in ordinary interiors, it serves as a reference point for normative studies of sound insulation and absorption.