Broadband Personal Sound Zone Control in the Presence of Nonlinearities

Abstract

Existing literature on sound zone control generally consider the signal model to be linear. However, this is seldom true in practice owing to nonlinear distortions arising from the loudspeakers, especially in consumer applications. In this paper, we propose a new signal model for personal sound zone control that takes into consideration any nonlinear behaviour that may arise from the loudspeakers. Following the proposed signal model, the optimization problem is formulated such that it inherently ensures the reduction of nonlinear distortion effects in both the bright and dark zones. In addition, a broadband nonlinear acoustic contrast control - pressure matching approach is proposed for the new signal model. Simulation results on practical data show that our proposed approach can provide improvement in the acoustic contrast and/or the signal distortion performance compared to the traditional linear solution, in the presence of nonlinear distortions. Moreover, important observations are made for the study of nonlinear effects on sound zone control.