An auditory brainstem implant (ABI) is a medical device that is implanted in the brainstem to help individuals who are deaf or severely hearing-impaired to perceive sound. Unlike cochlear implants, which are designed for individuals with deafness in the inner ear, ABIs are used for people who have hearing loss due to damage in the auditory nerve or brainstem.
An ABI consists of an external speech processor and an implanted electrode array that is surgically implanted into the brainstem. The speech processor picks up sound and converts it into electrical signals that are transmitted to the electrode array. The electrical signals stimulate the auditory nerve fibers, bypassing the damaged part of the auditory pathway and providing the user with a perception of sound.
ABIs are typically used for individuals who are not candidates for cochlear implants or who have not benefited from them. They are typically used for patients with cochlear nerve aplasia or NF-2. ABIs are considered a last resort for those who have exhausted all other treatment options and have little to no hearing left.