Current status and critical reflections on implantable hearing aids.

Objective: To present the technical background of implantable hearing aids and to consider biomechanical problems and selective criteria for candidates. Data Sources: Publications and evidence on biomechanical aspects of middle ear function. Conclusions: Implantable hearing aids represent a technically attractive and clinically promising challenge. Yet, the mechanical complexity of biotechnical interfaces in the middle ear and technical problems are immense and perhaps not even fully understood. Currently available devices still leave many biomechanical questions unanswered. Therefore candidates should be carefully selected to avoid unsuccessful implantations, in order to prevent a premature discredit of this fascinating technique.