Deafness can be divided into pre-speech and post-speech deafness depending on whether or not the person can speak. Pre-speech deafness is deafness that occurs before speech, and therefore the opportunity to learn to speak is lost. In addition to restoring hearing, prelingual deafness requires language acquisition. The younger the age of implantation, the better the results. Older deafness is a post-lingual deafness and requires only a short period of auditory training after surgery, not speech training. There is no age limit for the implantation procedure, and anyone in good health who can receive general anesthesia is suitable for the procedure. The oldest person who underwent the surgery in our hospital was 60 years old, and the oldest age of foreign patients was 89 years old. In addition to the age factor, the conditions that make a patient suitable for surgery are ① Patients should be profoundly or totally deaf in both ears, i.e., unable to understand speech with the help of hearing aids; ② No external or middle ear diseases or serious systemic disorders; ③ Possess a stable psychological condition and have a correct understanding of the effects of surgery; ④ Ability to adhere to auditory training. When hearing cannot be restored with hearing aids, both children and elderly deaf people should receive cochlear implants as soon as possible. A cochlear implant should be received as soon as possible. Generally speaking, the shorter the time of hearing loss, the better the results after surgery. If the hearing loss is prolonged, the degeneration of the auditory nerve will increase. This will make training more difficult and affect the outcome of the surgery.