Bone anchored hearing aids are surgically implanted devices that bypass the auditory canal and middle ear, using direct bone conduction to transmit sound. People who experience frequent ear infections, single-sided deafness, or a rare congenital disorder known as external auditory canal atresia, in which the middle ear structures do not develop properly.
How Bone Anchored Hearing Aids Work
When normal hearing occurs, sound enters the external portion of the ear and is funneled through the ear canal into the cochlea of the inner ear. With some types of hearing loss, damage to the inner ear or auditory canal prevents sound from following this normal pathway.
Bone anchored hearing aids overcome this problem by utilizing the natural conductive abilities of bone to send sound vibrations directly to the inner ear, bypassing the auditory canal.
Bone anchored hearing aids consist of an external abutment, a sound processor, and a titanium implant, which eventually fuses with the skull brain in a process called osseointegration. Once this occurs, the unit can be fit and programmed. When functional, the sound processor captures sound vibrations and sends them through the external abutment to the implant, where nerve fibers are stimulated and hearing occurs. Bone anchored hearing aids provide a more natural sound, more clarity, and improved localization.
Individuals with unilateral hearing loss (single-sided deafness) will benefit most from bone anchored hearing aids, as will those who suffer from chronic ear infections; conventional hearing aids cause moisture and humidity to build up in the ear canals, exacerbating the condition. The procedure is considered safe, with little risk of complications.