US Patent 9930436 Bone conduction speaker

A bone conduction speaker is provided that, while it is a bone conduction speaker, additionally has a structure allowing a respiratory tract sound to be generated, thereby the high frequency characteristics thereof being improved. In the case where it is used by a hearing non-impaired person, communications at a good voice level can be made as well as in the case where it is used by a hearing impaired person. Further, when the hearing non-impaired person uses it to listen to a music, the music can be enjoyed with a high sound quality.