HEADPHONE, AND NOISE CANCELING CIRCUIT AND METHOD

摘要

PROBLEM TO BE SOLVED: To provide a noise canceling technique capable of suppressing noise in a high band. SOLUTION: A speaker amplifier 26 inverts the phase of a sound signal S2 collected by a microphone 16 for superposition to an input audio signal S1, and drives a speaker 14. A filter 40 is provided between the speaker amplifier 26 and the speaker 14, and has variable passing characteristics. The filter 40 can switch between a state in which an output signal of the speaker amplifier 26 is not affected and that in which an output of the speaker amplifier 26 is filtered. COPYRIGHT: (C)2009,JPO&INPIT