Bone-Conduction Device Technology
Bone-conduction devices are also known as bone-conductor implants, bone-conduction stimulators, or bone-anchored hearing aids. These devices can either be implanted or worn. This type of technology directly transmits sound vibrations to the inner ear via bone conduction, bypassing the ear canal and the middle ear, and stimulating the inner ear through the skull.
Bone-conduction devices are recommended for patients with conductive hearing loss, mixed-hearing loss, or single-sided deafness. These devices are good alternatives for patients who cannot wear hearing aids due to problems in the outer or middle ear.
Bone-conduction devices are comprised of three parts. An external audio processor contains the battery, microphone, and digital signal processor. These devices can be worn behind the ear and hidden underneath the hair, or applied to a tooth like a retainer.
Some types require a surgically implanted titanium abutment placed behind the patient’s ear and embedded in the temporal bone. The titanium abutment secures the external audio processor in place.
The audio processor records sound and converts it into signals, which are transferred through the skin to the titanium implant. The implant transforms the signals into mechanical vibrations that are transmitted to the surrounding bone. The bone conducts the vibrations to the inner ear, where they are converted and transmitted as impulses to the patient’s auditory nerve, much like the natural hearing process.
Other types of bone-conduction devices use a magnetic connection. The magnet is implanted against the skull behind the patient’s ear, which anchors the sound processor to the patient’s scalp.