A Fast Reduced-Rank Sound Zone Control Algorithm Using The Conjugate Gradient Method

Sound zone control enables different users to enjoy different audio contents in the same acoustic environment. Generalized eigenvalue decomposition (GEVD)-based methods allow us to control the tradeoff between the acoustic contrast (AC) and signal distortion (SD). However, such methods have a high computational complexity. In this paper, we propose a fast reduced-rank sound zone control algorithm using the conjugate gradient (CG) method. Instead of using the eigenvectors as the basis for the solution space, the search directions in the CG method are used to reduce the computational complexity. Then, a low dimensional EVD is applied to obtain the sub-optimal control filter coefficients. The dark zone power can be adjusted by a parameter, which implicitly controls the trade-off between the AC and SD. Compared with GEVD-based methods, experimental results show that the proposed algorithm has a degradation of performance (4-5 dB) in terms of AC or SD but a high improvement on computational efficiency.