There are many design methods of the feedback active noise control system to obtain both good noise reduction performance and sufficient stability, which can be roughly divided into two categories: the non-adaptive and the adaptive methods. the non-adaptive methods design the feedback controller by formulating the performance specifications from practice into the optimization problem with various design criteria and constraints, then some optimization algorithms are used to search the solutions. The adaptive methods are based on the adaptive algorithms and then can be applied to the online feedback ANC system. This paper aims to investigate the effectiveness of these methods via an ANC headrest implemented on a floating point digital signal processing platform. Detailed performance of the ANC headrest designed by these methods is tested respectively in an anechoic chamber. The advantages and disadvantages of these methods are summarized to provide reference for their practical application.

Noise; Active control; Feedback; Waterbed effect