[Physical audiological principles of implantable hearing systems : About power transmission, coupling and power output].

Implantable hearing systems work because mechanical vibration energy is introduced into the hearing system. The performance of the hearing system is thus essentially determined by physical parameters. Together with the tone and speech audiogram the indications for deciding on a system are based on the efficacy of the respective system and the patient's wishes. Hearing-assisted patients should have a dynamic range of 30-35 dB to adequately understand speech. This should be guaranteed with the respective system also in the medium to long term. In addition, sufficient cochlear reserve performance for implantable hearing systems is critical for success. The expected and achieved audiological success can be the effective gain as a difference of aided hearing threshold to bone conduction threshold and should be preferred to the unreflecting use of gain or functional gain. With good differential diagnostic indications and the inclusion of conventional hearing aids and cochlear implants, optimal hearing solutions can be found for almost all patients.