[First implantation of a totally implantable electronic hearing aid in patients with inner ear hearing loss]

For the majority of patients with sensorineural hearing loss (SNHL) many available hearing aids often do not achieve satisfactory results. For these patients partially implantable hearing devices have been developed, allowing distortion-free hearing and speech intelligibility that may be superior to conventional hearing aids. The external parts of partial implants, however, may result in a patient's stigmatization. Furthermore, they do not use the acoustic properties of the external auditory canal. Recently, we published the successful development of the first totally implantable hearing device for the treatment of SNHL (HNO 46 [1998] 853-863). Here we report the first implantations of this unique, totally implantable electronic hearing system in patients with SNHL: Implex TICA LZ 3001. The implant microphone is implanted subcutaneously in the outer ear canal near the ear drum. The signal is processed by a digitally programmable multichannel audioprocessor located subcutaneously on the bony skull behind the ear. A piezoelectric transducer is coupled to the body of the incus and drives the ossicular chain by vibratory actions. Energy is provided by an implantable battery. Implanted patients describe hearing as being distortion-free and transparent. Speech intelligibility and the hearing of music are improved. Patients may achieve better speech discrimination, especially in the presence of background noise. The aid can be used during sports, including swimming. To our knowledge, this is the first report of the implantation of a totally implantable electronic hearing system in patients. These results encourage further implantations of the totally implantable hearing system in the course of an ongoing clinical study.