Point‐to‐Point Correlation of Sound Pressures in Reverberation Chambers

Point‐to‐point correlations of reverberant sound fields are important both for high‐intensity noise tests of spacecraft and for exploring the state of diffusion of the sound field. The classic paper on reverberant field correlation by Cook and others [J. Acoust Soc. Amer. 27, 1072 (1955)] derived a narrow‐band correlation coefficient of (sin kr)/kr, where r is the separation of any two points considered, on the assumption that the field is completely diffuse. The primary intent of the present paper is to consider the actual reverberant mode shapes of a rectangular room and, without any assumptions concerning diffusion, show that the correlation can approach Cook's formula. The treatment sheds some light on conditions that alter the correlation. For example, extreme symmetry in the chamber, noise source, and measurement points can increase the point‐to‐point correlation. The derivation can be a point of departure for computer programs to study the correlation in particular situations. These should be quite...