METHOD FOR ENHANCING NOISE-CANCELLING AMOUNT OF FEEDBACK ACTIVE NOISE-CANCELLING HEADPHONES, AND ACTIVE NOISE-CANCELLING HEADPHONES

摘要

Disclosed are a method for enhancing noise reduction amount of a feedback active noise reduction headphone and active noise reduction headphones. The method comprises: arranging a noise reduction microphone of the feedback active noise reduction headphone at a position away from directly in front of a loudspeaker; and adjusting a relative position between the noise reduction microphone and an ear canal opening of a wearer, and enabling an open-loop transfer function at the ear canal opening L2(s0) and an open-loop transfer function at the noise reduction microphone L1(s0) to satisfy a relation of |L2(s0)||L1(s0)|, to enhance an actual noise reduction amount at the ear canal opening. When the method is applied to a supra-aural feedback active noise reduction headphone, it can solve the problem of thickness increase in the supra-aural earphone or wearing discomfort resulted from installing a noise reduction microphone directly in front of a speaker. When the method is applied to a circum-aural feedback active noise reduction headphone, it can solve the problem in the prior art that a noise reduction amount is considerably reduced at an ear canal opening of the wearer since a relatively thick filler is used or a circuit gain is attenuated between a speaker and the ear canal opening of the wearer to avoid howling.