Multi-channel active noise control with freely movable error microphones

In this paper, we present a novel multi-channel active noise control (ANC) system with freely movable error microphones. This ANC system uses a simultaneous perturbation algorithm and has an advantage that secondary path models (estimation of secondary paths) are not required unlike the conventional MEFX (multiple error filtered-X) based ANC. This system can consequently control noise stably because there are not modeling errors which cause system instability. The computational complexity is also very small. We demonstrate that the proposed multi-channel ANC system can operate stably under an environment where the error microphones always move.