In the past… people with severe hearing loss or deafness could sometimes use hearing aids… but for some, they were ineffective or only slightly effective. The “cochlear implant” is a new electronic device evolution that helps increase the chances for those with hearing loss… to be able to perceive sound like normal people again!
Getting to Know… Cochlear Implants
Cochlear implants or electronic devices function as substitutes for nerve cells in the cochlea of the inner ear by converting sound energy into electrical signals to stimulate the auditory nerve and brain to perceive sound. The cochlear implant is divided into 2 parts:
- External device (Sound processor) receives sound signals from the environment via a microphone, then converts the sound signals into digital signals before transmitting them to the transmitting antenna and headpiece to send into the internal device.
- Internal device (Implant) after receiving digital signals from the external device, converts them back into electrical signals, which are then sent through electrode wires to the electrode array surgically implanted along the length of the cochlea. The electrical signals stimulate the auditory nerve endings and send signals to the brain for interpretation.
Cochlear implants are suitable for these individuals…
- Young children with severe hearing loss from birth, who if operated on before the age of 2, can develop comparably to normal children.
- Adults with severe hearing loss for whom hearing aids are ineffective or minimally effective.
- Children over 2 years old with hearing impairment greater than 90 decibels, although surgery requires consideration of other hearing test results.
Before surgery, patients must undergo a computed tomography (CT scan) of the inner ear, blood tests, and other physical examinations to assess suitability for surgery, including psychiatric or psychological evaluations to assess intelligence, emotional, and social normality, which are important factors in determining whether the patient should undergo surgery.
Factors Affecting the Effectiveness of Cochlear Implants
- The patient’s perception and ability to distinguish sounds before surgery.
- The cause of hearing loss, as some diseases causing hearing loss may limit surgery options.
- Patients who previously had language perception and then lost hearing benefit more than those born deaf.
- Patients operated on at a younger age benefit more from cochlear implants than those operated on at an older age.
- The sooner the surgery is performed after hearing loss, the better the hearing and listening recovery.
- Different models and brands of cochlear implants have varying technologies, which affect patients differently.
