Computer prediction of sound distribution in enclosed spaces using an interference pressure model

Abstract Current computer models for the prediction of sound distribution in enclosed spaces use intensity to represent the sound radiating from various sound sources. This approach reduces the amount of information to be calculated and makes the modelling system simple enough to be represented on a desktop computer. With the advent of new computer technology it has now become practical to model sound distribution using pressure, including phase information, in empty enclosed spaces. Measurements taken have shown that in empty enclosed spaces sound interference can be observed both close to and, to a lesser extent, far from the sound source. Independent measurements have also shown the measured sound pressure level at the same floor position to fluctuate significantly with receiver height. A comparison of predictions by both an intensity and a pressure based model showed that the general shape and accuracy of the propagation curves predicted by the pressure model were similar to those measured, whereas the intensity based model gave curves that did not predict interference effects.