The future of bone conduction hearing devices.

The bone-anchored hearing aid (Baha) is today an important rehabilitation alternative for patients with mixed and conductive hearing loss and where air conduction devices should not or cannot be used. Some patients with single-sided deafness are also successfully treated with a Baha. Despite successful treatment of these patient groups, there is always a need for future improvements. First, it is well known that Baha are associated with some drawbacks related to skin infections, accidental or spontaneous loss of the bone implant, and patient refusal for treatment due to stigma. Therefore, in this chapter some alternatives to the Baha which have the potential to reduce these drawbacks are generally discussed. They all have the common feature that they do not need a permanent skin penetration. The alternatives to the Baha are: (1) improved conventional bone conduction (BC) devices, (2) devices with an implanted transducer referred to as BC implants (BCI), (3) dental-attached devices. Disregarding skin complication issues, direct BC devices like the Baha, have a superior advantage of better sound quality in the high-frequency range. How these devices might be improved in the future is also discussed. Finally, some recent advances in the development of a new BCI system will be presented, where the implanted transducer uses a non-screw attachment to a hollow recess of the temporal bone. Some preclinical studies have been performed showing that a BCI system can provide similar or higher output as compared with a Baha.