Different people may have different hearing problems. Some people may have mild to moderate low frequency hearing loss. Some people may have a profound hearing loss in higher frequencies in both ear. For minor hearing difficulties, conventional hearing aids usually can help you achieve better hearing experience. But for those who have profound hearing loss in both ears and receive little or no useful benefit from hearing aids, then cochlear implants may be suitable solution.
A cochlear implant is very different from a hearing aid. Hearing aids amplify sounds so they may be detected by damaged ears. Cochlear implants bypass damaged portions of the ear and directly stimulate the auditory nerve and thus provide a most natural hearing experience. The cochlear implant does not result in "restored" or "cured" hearing. It does, however, allow for the perception of sound "sensation". Cochlear implants have external (outside) parts and internal (surgically implanted) parts. The external parts include a microphone, a speech processor, and a transmitter. The internal (implanted through Cochlear Implant Surgery) parts include a receiver and electrodes. There are broad spectrum of different electrode arrays, and each is designed to match specific clinical requirements (from individuals with cochlear ossifications to those with residual hearing).
The use of a cochlear implant requires both a surgical procedure and significant therapy to learn or relearn the sense of hearing. The decision to receive an implant should involve discussions with medical specialists. Usually, teams of professionals (audiologist, otologist/surgeon, medical specialists as needed, psychologist, counselors, and speech-language pathologists) will determine candidacy for an implant, perform the surgery, and provide follow-up care to cochlear implant recipient. The process can be expensive. Surgical implantations are almost always safe, although complications are a risk factor, just just as with any kind of surgery. Hearing through a cochlear implant is different from normal hearing and it requires you to learn to interpret the sounds created by an implant. Not everyone performs at the same level with same implant and this process takes time and practice.