The bones of the skull are capable of transmitting sound energy to the inner ear, and this is the basis of bone conducting hearing aids and tuning fork tests. However, a traditional bone conducting aid can be uncomfortable, as it has to be pressed against the skull, and is inefficient, as transmission through scalp skin results in significant loss of energy. A bone anchored hearing aid circumvents these problems by implanting a titanium fixture and attaching a hearing aid to the fixture. Sound energy is amplified by the hearing aid and transmitted to the inner ear via the fixture and skull bones, bypassing the conductive loss. As there is little attenuation of energy across the skull, the contralateral cochlea is also stimulated.
The main implantable bone conducting hearing devices are:
The BAHA Formerly owned by Entific, now by Cochlear. The Ponto device from Oticon is very similar.