Experiences with implantable hearing devices and a presentation of a new device.

Following animal experiments, anatomic examinations, and histologic studies, an implantable hearing device was developed. This device, the temporal bone stimulator (TBS), uses an inductive coil without percutaneous connection that transmits bone-conducted vibrations to the inner ear. Ten patients have been implanted and followed by the Central Ear Research Institute. The TBS is effective and may have wide application in producing amplification in good sound fidelity when used in patients who have external canal, middle ear, or eustachian tube disease that is poorly corrected by surgery or conventional hearing aids. The utilization of similar principles of electromagnetic transfer of energy directly to the ossicles appears reasonable and is potentially highly rewarding for those who have sensorineural hearing impairments with thresholds greater than 40 dB. The enormous potential benefits derived from the application of these implantable hearing devices is worthy of the greatest effort in future otologic investigation.