A cochlear implant is an electronic device that replaces the function of the human ear and helps adults and children who are severely or profoundly deaf to restore or provide the sense of hearing and improve the ability to communicate with others. The cochlear implant consists of electrodes and receivers implanted in the human body, as well as a speech processor, directional microphone and transmitter carried outside the human body. The sound is received by the directional microphone and converted into an electrical signal and transmitted to the speech processor, which amplifies and filters the signal and transmits it from the transmitter to the receiver, where it generates electrical impulses that are transmitted to the corresponding electrodes, thus causing excitation of the auditory nerve fibers and transmitting the sound information to the brain to produce hearing. As some patients with severe or very severe sensory hearing loss is more serious, the average hearing threshold of speech frequency is often more than 90 decibels, even after the amplified sound is difficult to hear, the effect of wearing hearing aids is poor. This is because inner ear diseases, drug intoxication or other causes of damage to the sensory cells of the inner ear severely impede the transmission of auditory information, and the patient’s central auditory system cannot receive sufficient information despite the natural and clear sound amplified from the outside world. Cochlear implants can bypass the damaged structures in the inner ear and directly stimulate the auditory nerve, allowing patients to regain their hearing. Cochlear implants can help people who are severely or profoundly deaf communicate better with others, thereby allowing them to have more access to education and employment opportunities and to return to mainstream society.