Cochlear implant vs hearing aid: when a hearing aid is no longer enough

A hearing aid is a device worn in or behind the ear that picks up sound, makes it louder and clearer, and sends it into the ear for the person's own inner ear to detect. The NHS says hearing aids will not make hearing perfect but make sounds louder and clearer, reducing the impact of hearing loss. Importantly, the NHS notes that hearing aids only help if you still have some hearing left.

A cochlear implant is a different technology. RNID describes it as providing a sensation of hearing for people with severe to profound hearing loss by using electrical signals to stimulate the auditory nerve directly, bypassing the parts of the cochlea that are not working. It is therefore not a more powerful hearing aid; it is a replacement for part of the ear's own mechanism.

The NHS says a GP can refer you to a hearing specialist, who will discuss the types available, such as behind the ear (BTE), receiver in the ear (RITE), in the ear (ITE), in the canal and completely in the canal types, CROS and BiCROS for one-sided hearing loss, and body worn types for severe loss. Hearing aids are available free on the NHS as a long-term loan, with free batteries and repairs. These are usually BTE or occasionally RITE types, and other types may need private purchase.

After fitting, the aid is programmed to suit your hearing, you are shown how to use and look after it, and a follow-up appointment is arranged a few weeks later.

RNID explains that a cochlear implant has an external part, a microphone and a sound processor with a transmitter coil, which usually looks like a hearing aid on the ear with a cable to a transmitter held by a magnet behind the ear and can be removed, for example when sleeping. The internal part is a receiver fitted under the skin behind the ear with an electrode array that carries signals into the cochlea. This requires an operation.

The NHS describes the implant as turning sound into electrical signals sent to the cochlea and from there to the brain, and says an assessment is carried out beforehand. The implant will only work if the nerve that sends sound to the brain is working properly. If the hearing nerve itself is damaged, RNID says an auditory brainstem implant could help instead.

RNID says if you have severe to profound hearing loss in both ears and are not benefiting from hearing aids, a cochlear implant could be an option, and that your GP, audiologist or ENT specialist can refer you to a cochlear implant centre for assessment. A hearing implant may also be considered if you cannot use hearing aids for medical reasons.

Other implants exist for different problems. The NHS describes bone anchored hearing aids for hearing loss where sound cannot reach the inner ear, auditory brainstem implants for a problem with the auditory nerve, and middle ear implants for people who cannot use a regular hearing aid, for example because of allergy or poor fit. So the choice is not always only between a hearing aid and a cochlear implant.

If you are struggling to hear even with hearing aids, mention it to your audiologist or GP. A review of whether the hearing aids are suitable and correctly programmed is the usual first step before any decision about an implant. The NHS also stresses not delaying seeing a GP about hearing problems, because the earlier hearing aids are fitted the more benefit you may get.