One of the theoretical questions in interior noise is the connection between modal analysis and statistical energy analysis. Recently progress has been made in understanding this connection for structural vibrations including both fundamental theoretical work and experimental verification. It has been shown that statistical energy analysis is essentially an asymptotic limit of classical modal analysis. The basic asymptotic theory for structural wall-acoustic cavity interaction is described in this paper. Several numerical examples are presented for acoustic cavity response with a prescribed wall motion to illustrate the results of the theory.