Local active noise control using a novel method of designing quiet zones

This paper is concerned with sound minimization in space for local active control in pure tone diffuse fields. Theoretical studies have been performed to develop a new method of designing larger zones of quiet than are obtained with conventional systems. The principle of this new method is to maximize the area of the 10 dB quiet zones. This is in contrast to the conventional design methods, where the acoustic pressure or the acoustic pressure and particle velocity are set to zero at given cancellation points, or the acoustic pressure is minimized over an area using 2-norm and ∞-norm strategies. It is shown that larger zones of quiet are obtained using this new method. The preliminary experiment has also been carried out to validate the simulation results. The main contributions of the paper are that a novel method of designing active systems to generate larger zones of quiet is proposed and the performance of the active systems is analyzed through computer simulations and experiments.