Direct adaptive approach to multichannel active noise control and sound reproduction

A new direct adaptive approach is proposed for general multichannel active noise control (ANC) when all of the sound path dynamics are uncertain and changeable. To reduce the canceling errors, two kinds of virtual errors are introduced and are forced into zero by adjusting three adaptive FIR matrix filters in an on-line manner, by which the convergence of the actual canceling errors to zero can be attained at the objective points. Unlike conventional approaches, the proposed algorithm can give an adaptive feedforward controller directly without need of explicit identification of the secondary path channels, and requires neither any dither signals nor the PE property of the source signals, which is a great advantage of the proposed approach. The proposed multichannel approach is also applicable to multichannel sound reproduction (SR), in which the SR controller can be directly tuned without explicitly identification of room sound transmission channels.