A generalized method to optimize acoustic intensity field by using source array

Abstract

Acoustically bright zone is defined as a zone where the listener can acquire better sound quality than others. The acoustically bright zone can be generated by improving a desired acoustic variable on a selected zone, and the `zone control’ can be done by controlling multiple sources. Among many possible definitions on the acoustic variables, acoustic intensity is tried as an objective function to enhance the sound power radiation into the listening area. In previous work, acoustic intensity projected to a direction is considered as object function[J.-W. Choi and Y. –H. Kim, “Acoustic intensity optimization using source array,” in Proc. Inter-noise 2003, N777], so that one can maximize acoustic intensity component propagates to the desired direction. This approach shows that acoustic intensity field can be manipulated into a desired direction using a small number of sources, but it sometimes fails to control the direction of intensity. Extending this work, this paper presents a generalized method that can also manipulate the propagating direction of wave front. By employing normalized transfer functions between the multiple sources and measurement points during the optimization process, the directional characteristics of intensity field can be improved.