A Bone-anchored hearing aid is a type of hearing aid based on bone conduction. It is primarily suited to people who have conductive hearing losses, unilateral hearing loss and people with mixed hearing losses who cannot otherwise wear ‘in the ear’ hearing aids. The name BAHA is a trademark.
USE AND OPERATION
Bone-anchored hearing aids use a subcutaneous abutment which is attached to the skull. Thereafter the skin in closed and once the wound has healed, a small hearing aid attaches to the subcutaneous implant via a magnet. This then relays the sound in real time through the skull to the opposite ear enabling the person to have hearing on the “dead ear’s” side without them noticing the difference. The size of the hearing aid is approximately 2cm x 1cm square.
It relays the sound through bone and therefore leaves the ear canal open. Quite often with conventional hearing aids the ear canal tends to suppurate. It also enables people who have a one-sided hearing loss to have the BAHA placed on the dead ear’s side. The sound is then received on that side and in real-time relayed through the scull to the other ear, which enables the person to have near normal hearing as far as stereo and sound localization abilities are concerned.
This is not a substitute for a conventional hearing aid, but rather an adjunct in certain instances.
The benefits of Bone Anchored Hearing Aid such as BAHA are well documented. By bypassing the outer or middle ear, BAHA can increase hearing in noisy situations and help localise sounds. The benefit is not only improved speech understanding, hearing with BAHA results in a natural sound with less distortion and feedback when compared with conventional hearing aids. The ear canal is left open for comfort, and helps to reduce any problems caused by chronic ear infections or allergies. In patients with Single-sided sensorineural deafness (SSD), BAHA sends the sound via the skull bone from the deaf side to the inner ear of the hearing side. This transfer of sound gives a 360-degree sound awareness.