Patent ID: 8885865

Claim:
A sound-isolating earphone used by inserting a sound emitting portion into an external auditory canal entrance, comprising: an electro-acoustic transducer for generating a sound wave; and two independent sound leading pipes having different path lengths as a sound leading portion which transfers the sound wave generated from the electro-acoustic transducer to the external auditory canal entrance, wherein two sound waves generated from the electro-acoustic transducer and having passed through the two sound leading pipes are synthesized at the external auditory canal entrance, the path length difference between the two sound leading pipes is substantially equal to an interval between a sound emitting port of the sound-isolating earphone located in the vicinity of the external auditory canal entrance and the eardrum located in the depth of the external auditory canal, and a frequency equal to a primary resonance frequency of a both-end closed pipe resonance space is suppressed.