What are auditory brainstem implants?
Auditory brainstem implants (ABIs) are still a very new development. They work by bypassing the ear and auditory nerve and stimulating the auditory brainstem directly to provide a sensation of hearing.
Why might an ABI help?
ABIs are mostly used by adults who have suffered trauma to their hearing nerve and would therefore not benefit from hearing aids that amplify sound, or a cochlear implant that stimulates the hearing nerves.
What is an ABI and how is it different from a cochlear implant?
An ABI has two parts:
- the external part consists of the microphone and speech processor (which either sits behind your ear or is body-worn), a lead and a transmitter coil, and a microphone
- the internal part includes a receiver and a number of electrodes that directly stimulate your brainstem to provide a sensation of hearing. It's surgically implanted directly on to your brainstem, therefore bypassing the cochlea and auditory nerve.
A few weeks after the operation to insert the internal part, the external parts are fitted and your implant is switched on. The speech processor is tuned over a period of time to meet your needs. Following implantation, long-term support from professionals is crucial to encourage you to learn to listen to and understand the new signals from your implant.
When might I be offered an ABI?
ABIs have been used for adults who have been diagnosed with Neurofibromatosis Type 11 (NF2) (a condition causing tumours to grow on the hearing nerves), or who have suffered trauma to their hearing nerve. If the hearing nerve has been damaged, hearing aids and cochlear implants are of no benefit because sounds can't transfer from the ear to the brain along the nerve.
To find out more about auditory brainstem implants, see the National Institute of Clinical Excellence (NICE) guidelines for auditory brainstem implants.