2010 Volume 31 Issue 3 Pages 213-221
In this paper, we verify the performance of multiple-channel active noise control systems using the simultaneous equations method. This method has the advantage that it can automatically recover the noise reduction effect degraded by acoustic path changes. The method is hence applied to single-channel systems, and also it is shown that the method results in better performances than the filtered-x algorithm. In this paper, we extend the method to multiple-channel active noise control systems and verify the performance of the extended method by using impulse responses measured with an experimental system. The extended method is applied to a 1-2-2 system, consisting of one noise detection microphone, two loudspeakers and two error microphones, and to a 2-2-2 system including two noise detection microphones, resulting in noise reductions of 14 and 18 dB, respectively. This result demonstrates that the simultaneous equations method well works also for multiple-channel systems.