Active attenuation of nonlinear sound

摘要

Nelson and Elliot stated in their book Active Control of Sound that "it is the principle of superposition that enables the activ econtorl of sound t be accomplished" [1].The principle of superpositio is only valid in linear systems.Htis is apparently not a problem in most applicatiosn of activ nosie attenuaiton because the amplitude of sound is relatively small and linear osund propagation can be assumed,legitimately.