Further clinical experiences with middle-ear implantable hearing aids: indications and sound quality evaluation.

Since 1983, when the 5-year project on the middle-ear implantable hearing aids (MEI) was completed, we have been concentrating our studies on the clinical application of the partially implantable MEI (PMEI). The study was on the indication of implantation, improvement of the implantation operation, follow-up of the implanted patients, minor modification of the MEI, preparation of necessary surgical tools, and so on. Clinical study was also necessary for our team to finally confirm the clinical usefulness of this device. The present report is focussed mostly on the problem of indication for the application of PMEI.