Linear Systems Approach to Image Source Representations of the Sound Fields in Enclosures.

This study investigates the time-dependent behaviour of sound fields through the application of linear system theory to image source representations of various situations. Through the use of the vector-valued equivalent of the impulse response (which represents the direction and magnitude of the wavefronts comprising the one-dimensional impulse response), it is seen that one can obtain much information concerning the directionality characteristic of the behaviour of an acoustical system. Several situations are investigated in which Eigenfunction and Green's function solutions are compared to the linear systems approach. The behaviour of the acoustic fields are investigated and a discussion of the various methods of solution ensues. A technique is discussed which would permit the measurement of the time-dependent, vector-valued form of the impulse response in real situations, and an algorithm is developed for the inverse image source organization, in an attempt to characterize the shape of an enclosure from such information under the restrictions of specular reflection. A generalized approach to three-dimensional sound field reconstruction is presented, and methods of implementation of the aforementioned procedures are discussed.