What is a cochlear implant?
A cochlear implant can be life-changing technology for people with hearing loss. It consists of two parts that connect to each other with a magnet:
- An implant surgically placed in the inner ear.
- An external device worn on or near the ear.
The external piece, called a sound processor, takes incoming sound and sends it to the implant. The implant directly stimulates the hearing nerve to send the sounds that are picked up by the processor up to the brain, where they can be interpreted as speech, or music or environmental sounds.
The devices have been implanted in over 500,000 people worldwide since their development in the 1970s. Cochlear implants have been shown to reduce tinnitus (ringing in the ear), and improve people’s ability to understand speech. Implant recipients are often able to again participate in activities they found difficult with their hearing loss: attending church services, enjoying social gatherings and staying engaged in the workforce.
When are cochlear implants used?
Cochlear implants are no longer considered to be a last resort. When they were first developed, cochlear implants were recommended only when hearing aids didn’t help in either ear. Today more people can benefit from cochlear implants.
You don’t need to lose all hearing to receive an implant. For example, if your hearing aids work but don’t provide as much speech understanding as you’d like, cochlear implants can help. Many people with cochlear implant today have remaining “residual” hearing that helps them to hear some words and sounds, especially low-pitched sounds like vowels. That hearing can supplement what the cochlear implant provides.
For some people that means continuing to use a hearing aid in the unimplanted ear. For others, it means hearing amplified low pitches (similar to using a hearing aid) plus having the cochlear implant improve hearing for the higher pitches (like consonant sounds). You don’t have to wait until you’re struggling to hear well in both ears before considering an implant. Cochlear implantation can be done even if only one ear benefits.
Recipients do best with implants if they receive them as soon as possible after they become a candidate.
How is a cochlear implant different from a hearing aid?
Hearing aids amplify sounds louder so the hearing system can process them better. They are effective for people who need certain sounds to be louder in order to hear them clearly. Sound still travels through all the portions of the ear (outer ear, middle ear, inner ear) to the hearing nerve. But for some people, simply making sounds louder may not be enough to improve their clarity. They may be able to hear but not understand words clearly.
A cochlear implant essentially replaces key parts of the hearing system when they are no longer working optimally. The implant bypasses these structures and directly stimulates the hearing nerve with electrical energy. As a result words can be much clearer.
Learning to hear and understand with a cochlear implant take time and practice. Sounds are delivered to the hearing nerve in a very different way than they are with natural hearing or hearing aids. The brain needs to learn how to make the best use of the new sound it can hear.
An audiologist or auditory-based therapist can provide guidance about how to learn to hear best with a cochlear implant. Generally, improvement can be measured by one month of device use, and progress often continues for the next three to six months.
How do I know if I’m a good candidate for cochlear implants?
Determining if a person is right for cochlear implants is a process and requires input from a number of team members, including a surgeon, audiologist and, in some cases, an auditory-based therapist. You may need to take any or all of the following steps:
- Comprehensive audiologic diagnostic testing: You should have had a recent hearing test. These tests assess hearing loss and help to choose the best follow-up services and/or technology.
- Cochlear implant evaluation: Your current hearing aids will be checked to see how well they work and how well they allow you to function. This test will show if your hearing aids are giving you optimal hearing or if implants should be considered.
- MRI and/or CT scan: These tests show the internal structures of the inner ear.
- Medical and surgical consultations: The surgeon will meet with you before surgery to discuss instructions, the procedure and what to expect after surgery in terms of healing and possible hearing outcomes.
- Communication evaluation: Auditory, speech and language skills are evaluated.
- Balance assessment: Testing is done to evaluate the vestibular (balance) system. The system is closely linked to the structures involved in hearing.
What can I expect with a cochlear implant?
The cochlear implant surgical procedure is usually performed as an outpatient surgery. In the time after surgery, an expert team works closely with each patient.
All people who receive cochlear implants can detect sound, including speech, at comfortable levels. Most people with implants develop the ability to recognize and understand speech in quiet environments without visual cues. Many can use the phone, appreciate music and converse successfully.
The best results are seen in patients who have shorter durations of severe-to-profound hearing loss. But even if the hearing loss began decades ago, cochlear implants can be helpful. Some listening environments, such as those involving background noise or those without visual cues, such as talking on the phone, are particularly hard. Auditory therapy and cochlear implant reprogramming may improve performance.
However, success in these challenging environments varies greatly among recipients. Learning to hear and understand with a cochlear implant takes time, practice and, initially, frequent programming appointments. Those who commit to participating in daily “exercise” using the processor generally see the quickest improvement.
Recovery and Outlook
What are the outcomes and benefits of cochlear implantation?
Both adults and children can benefit from cochlear implants. The age of patients who have received these implants ranges from 8 months to over 90 years. However, sometimes cochlear implants do not restore normal hearing function. Performance varies based on a multitude of factors, including:
- Duration of hearing loss.
- Consistent use of amplification prior to cochlear implantation.
- Cause of hearing loss.
- Age of hearing loss onset.
Success with a cochlear implant can't be predicted. However, the following factors tend to suggest the likelihood of a good outcome:
- Pre-implantation hearing system status.
- Exposure to sound (and especially speech) before loss of hearing.
- Shorter duration of hearing loss.
- Consistent use of amplification prior to implantation.
- High number of functioning hearing nerve fibers.
- Lack of anatomical complications.
- Consistent use of the cochlear implant.
- Daily use during all waking hours.
- Attending scheduled appointments.
- Participating in auditory therapy.
- Consistently developing and implementing strategies for listening and speaking (pediatrics).
- Educational placement that emphasizes auditory skill and spoken language development.
- Realistic goals and sincere desire to be part of the (re)habilitation process.