Modified hybrid active noise control system

The paper presents an architecture of a Hybrid Active Noise Control (ANC) system, which is a combination of the Feed-Forward (FF) and Feed-Backward (FB) ANC systems. A modification of the ANC system, known for the FF case only, is extended to the Hybrid ANC system. The modification allows to accelerate the adaptation process, if the gradient search based adaptive filtering algorithms, like Least Mean Square (LMS), are used. Besides, it allows to use the more efficient Recursive Least Squares (RLS) adaptive filtering algorithms, which cannot be used in the unmodified ANC system. Simulation results for the attenuation of the band-limited polyharmonic and wide-band noise are presented. The results demonstrate the proposed ANC system efficiency when the LMS and RLS algorithms are used.