Active suppression of narrowband noises in 3D sound fields

This paper presents a simple multiple-input-multiple-output (MIMO) controller for active suppression of narrowband noise in 3D sound fields. The controller only depends on a complex matrix H(jω0) instead of an n × n transfer matrix to model the secondary paths. Unlike other available ANCs that obtain the controller transfer functions by adaptation, the proposed one solves its controller transfer matrix directly from H(jω0); and tolerates some degrees of errors in H(jω0). If necessary, the proposed system may be made adaptive to trace the drifting secondary path. Online identification of a matrix H(jω0) is easier than that of a transfer matrix with many coefficient matrices. The estimate would be more accurate for H(jω0) if other conditions remain the same. The proposed scheme can be modified to suppress narrowband noises with multiple bands by a moderate increase in complexity.