Application of a Disorder Measure to Acoustical and Structural Models

The interaction of structures and sound fields frequently involves many degrees of freedom of each participant in a complicated interaction process. In one way or another, statistical or deterministic models of the systems involved are applied in such problems and the resulting vibration (or radiation) is calculated, frequently to a satisfactory degree of accuracy. At other times, however, the results of these calculations suggest that a statistical rather than deterministic model might have been more satisfactory (or vice versal). What is clearly lacking is an a priori criterion for deciding whether a statistical or deterministic model of a system/response situation is more appropriate. The purpose of this paper is to discuss the manner in which a measure of disorder similar to those employed in other areas of technology might be calculated for problems in sound and vibration.