Hearing and speech are important means for human beings to communicate with each other and to understand the world, however, the gloom of ear diseases and hearing impairment is attacking human beings. According to the estimation of the World Health Organization, there are nearly 600 million people with mild hearing loss and 250 million people with hearing loss of moderate degree or above in the world. In China, there are 20.57 million people with hearing impairment, ranking first among all types of disabilities, accounting for 16.79% of the national population, of which 800,000 are deaf children under the age of seven, and more than 30,000 new deaf children will be produced every year. Hearing impairment seriously affects the social interaction and personal quality of life of these people. The sounds we hear are actually vibrating waves of a certain frequency range – sound waves – emitted by a certain sound-producing body. The human auricle is like a satellite receiver that receives sound waves and converges them to the outer ear canal and then to the eardrum, where the vibration of the tympanic membrane drives the auditory ossicles that are connected to it, and the activity of the auditory ossicles transmits the vibration to the inner ear. Hair cells in the inner ear convert sound signals into bioelectrical signals into the auditory nerve, and then through the auditory nerve to the hearing center of the brain, through the auditory center of the brain to analyze and produce hearing, from which we can really “hear” the sound. Deafness can be caused by many factors. Depending on the part of the ear affected, we can categorize deafness into three types: conductive deafness, sensorineural deafness and mixed deafness. Sensorineural deafness is mainly caused by missing or damaged hair cells in the cochlea and is usually permanent. Cochlear implants, the only effective treatment for restoring partial hearing to patients with severe and profound deafness, were first developed in the 1950s, but were not used in clinical practice until more than 20 years ago. The cochlear implant or “bionic ear” is a high-tech marvel. A cochlear implant is a special acoustic-electrical conversion device that works by converting sound signals from the environment into electrical signals, which are transmitted to the patient’s cochlea through implanted electrodes to stimulate the cochlea’s residual auditory nerves, thereby producing hearing. The fundamental difference between cochlear implants and hearing aids is that cochlear implants can bypass the damaged inner ear and directly stimulate the auditory nerve fibers, allowing the patient to regain hearing, whereas hearing aids cannot. Cochlear implants are suitable for people with severe to profound hearing loss. Cochlear implants are not suitable for all deaf patients. Children with severe malformations in the inner ear, no cochlear deformity, severe mental retardation, inability to cooperate with speech training, and poor physical condition and uncontrollable epilepsy are not eligible for cochlear implantation. The applicable criteria for cochlear implantation are: ① the best age for prelingual deafness is 12 months to 5 years old, and postlingual deafness at all ages; ② severe or very severe sensorineural deafness in both ears; ③ no effect or poor effect of wearing suitable hearing aids; ④ no contraindications to surgery; ⑤ the family and/or the implantee themselves have a correct understanding of the cochlear implantation and appropriate expectations; ⑥ there are conditions for hearing and language rehabilitation education. The cochlear implant does not mean that the child will speak naturally. Auditory-verbal rehabilitation training is an important part of whether a deaf child patient can return to the sound world after cochlear implantation. Cochlear implants enable deaf people to say goodbye to the silent world, to listen to language, to perceive the sounds in the surrounding environment, and to enjoy beautiful music.