Real-time active suppression of scattered acoustic radiation

Active noise control usually aims at reducing the total acoustic pressure due to a noise source; it may also be used in principle to reduce the scattered acoustic radiation from a reflecting body in order to render it invisible to incident acoustic waves. In this paper, a real-time control strategy is introduced to achieve, with ordinary noise sources and sensors, the effective suppression of the noise scattered by a 3-D surface. Numerical simulations of 2-D and 3-D control are used to illustrate the potential of this control strategy. Preliminary experimental results are also given for the 1-D case of a rigid body inserted into a duct.