Local Active Sound Control Using the Remote Microphone Technique and Head-Tracking for Tonal and Broadband Noise Sources

Local active sound control can be combined with the remote microphone technique and head-tracking for the case when direct measurement of the error signals at a listener’s ears is not possible and the position of the listener’s head is continuously changing. This paper presents the performance of the combined active control system when it is applied to reduce either tonal or broadband random noise. First of all, effects of the combined system were experimentally investigated when periodic noise from a single primary source was adaptively controlled in real time. By directly applying observation filters and acoustical responses in the frequency domain, it was shown that active control of tonal noise can be effectively improved by the remote microphone technique and head-tracking. In addition, the ability of the combined active control system to control stationary random broadband noise was investigated. However, in this case, the causality of the observation filter must be considered due to the unpredictability of random noise. Therefore, the causally constrained remote microphone technique and the corresponding broadband active noise control system were studied.