Patent ID: 8934638
Filing Date: 2015-01-13
Classification: G10K,H04R

Abstract:
1. A feed-forward noise canceling headphone of one of an on-ear type and an ear-muff type, comprising: a front air chamber defined by an ear pad that abuts on a user, an external-ear canal of the user, and a housing; an air chamber containing empty free space that is a space separate from the housing and the front air chamber, wherein said air chamber is sealed by the housing and a member that covers an outer circumference of the housing, and wherein said air chamber is arranged outside the front air chamber; a microphone attached to the housing, wherein a sound-wave introducing part of the microphone is provided in the air chamber, and wherein a noise-canceling signal is generated by a circuit in response to an external-noise signal generated by the microphone; and a headphone unit driven by the noise-canceling signal to output a canceling sound to the user, wherein the air chamber functions as a pressure acoustic field such that sound waves of an external noise that reach the air chamber having a wavelength longer than or equal to a maximum linear length of the air chamber are uniformly transmitted all over the air chamber, and wherein the microphone collects the external noise reaching the air chamber before the external noise reaches the front air chamber.