The internal receiver and electrodes of an Auditory Brain Stem Implant (Image courtesy of Cochlear™ Ltd).
Auditory Brainstem Implants are a small surgically implanted device connected to the brain stem of recipients with severe auditory nerve damage or profound Sensorineural Hearing Loss that results in an absence of any hearing ability.
Severely auditory nerve damage means the Cochlea – the organ that senses sound – cannot relay sound information to the Brainstem and then the rest of the brain. As a result, Hearing Aids or Cochlear Implants are unable to help individuals with severe auditory nerve damage.
One condition where an Auditory Brainstem Implant may be used is when a certain kind of tumour known as Neurofibromatosis Type 2 (NF2) occurs on the auditory nerve. Often in the process of removing a NF2 tumour, the auditory nerve is severed resulting in the complete loss of hearing in the affected ear. As this condition is rare and the surgery required very delicate and precise, Auditory Brainstem Implants are often the only viable hearing technology option for this very small group of people.
Auditory Brainstem Implants are similar in design and operation to Cochlear Implants. They have a receiver and an electrode surgically implanted electrode along with a magnetic coil and a sound processor worn behind the ear. Unlike Cochlear Implants, the electrode is placed on the surface of the Brainstem rather than being inserted into the Cochlea.
A person with an Auditory Brainstem Implant cannot usually distinguish between different sounds but instead that have an ability to know when sound is present or absent, which can assist with lip reading.
Watch the video below to find out more about how an Auditory Brainstem Implant works.