For centuries, people believed that only a miracle could restore hearing to the deaf. It was not until forty years ago that scientists first attempted to restore normal hearing to the deaf by electrical stimulation of the auditory nerve. The first experiments were discouraging as the patients reported that speech was unintelligible. However, as researchers kept investigating different techniques for delivering electrical stimuli to the auditory nerve, the auditory sensations elicited by electrical stimulation gradually came closer to sounding more like normal speech. Today, a prosthetic device, called cochlear implant, can be implanted in the inner ear and can restore partial hearing to profoundly deaf people.
These implants usually consist of 2 main components:
- The externally worn microphone, sound processor and transmitter system.
- The implanted receiver and electrode system, which contains the electronic circuits that receive signals from the external system and send electrical currents to the inner ear.
Benefits of Cochlear Implants:
- Adults often benefit immediately and continue to improve for about 3 months after the initial tuning sessions. Cochlear implant users’ performances may continue to improve for several years.
- Users perceive loud, medium and soft sounds. People report that they can perceive different types of sounds, such as footsteps, slamming of doors, sounds of engines, ringing of the telephone, barking of dogs, whistling of the tea kettle, rustling of leaves, the sound of a light switch being switched on and off, and so on.
- People with cochlear implants can also understand speech without lip-reading.
- Users are able to make telephone calls and understand familiar voices over the telephone. Some good performers can make normal telephone calls and even understand an unfamiliar speaker.
- Many can watch TV more easily, especially when they can also see the speaker’s face.
- Some users can enjoy music. Some enjoy the sound of certain instruments (piano or guitar, for example) and certain voices.
The best adult candidates to use cochlear implants:
- Have severe to profound hearing loss in both ears
- Have had limited benefit from hearing aids
- Have no other medical problems that would make the surgery risky
- Have a strong desire to be part of the hearing world and communicate through listening, speaking, and speech reading
- Have lost their hearing after speech and language development
Children can also be considered for cochlear implants. Children as young as 14 months of age have received cochlear implants, and the potential exists for successful implantation at younger ages.
Keep in mind that the patient’s willingness to experience new acoustic sounds and cooperation in an auditory training program are critical to the degree of success with the implant. The duration and complexity of the training varies from patient to patient.