For the intractable conductive hearing loss in spite of many surgical trials, the conventional hearing aid is significantly beneficial. But, in congenital or acquired external canal atresias, persistent otorrhea after radical mastoidectomy with ear canal defects, or chronic external canal dermatitis by prolonged use of hearing aid, conventional type may not be useful. Surgically uncontrolable tympanic cavity atelectasis, congenital ossicular malformations, and massive tympanosclerosis which are unable to properly use a conventional hearing aid have a problem, too. A new developed implantable bone conduction hearing device does not use the ear canal but temporal bone to conduct the sound from external area to the cochlea and can be helpful for the above mentioned patients. We expirienced 2 cases of hearing device implantation for bilateral congenital microtia with external canal atresia and persistent pus otorrhea from both ears after both sided radical mastoidectomy in a childhood, and report the indications and surgical procedures here.