History Cochlear implants began internationally in France and the United States in the late 1950s. In the last decade or so, with the development of modern high technology, cochlear implants have progressed rapidly, from single-channel devices that could only help patients with lip reading in the early days to modern multi-channel devices that allow most patients to make phone calls. Many deaf children with cochlear implants have gone through years of auditory-verbal rehabilitation and have entered normal schooling. Cochlear implants have moved from experimental research to clinical application, and medical societies in Europe and the United States have adopted cochlear implants as a routine treatment for profound and total deafness. Progress In China, a single-channel cochlear implant device was successfully developed by Peking Union Medical College Hospital in 1980, enabling patients with total deafness to hear environmental sounds and restore their sense of sound. Because the single-channel device was limited by the small amount of input information and the sealing problem of the implanted part was not well solved, the results were not satisfactory. Since 1995, Peking Union Medical College Hospital and some other hospitals in China have introduced multi-channel devices from Australia and other countries, and successfully performed surgical implantation for totally deaf adults and children, and obtained satisfactory results. Some of the postlingual deaf patients have been able to use the telephone, and most of the prelingual deaf children patients have started to speak and enter normal elementary schools after a period of auditory language training. Benefits While the primary goal of cochlear implants is to enable deaf individuals to understand and learn language, the benefits of cochlear implants are not limited to this. Cochlear implants have a positive impact on the mental health of the individual and on the economic benefits to society. For adult implant recipients, personal mental health benefits include reduced isolation and depression, increased self-esteem and self-reliance, and easier integration into society and job opportunities. Data on the benefits of cochlear implants for children are incomplete, but what data is available shows that children with cochlear implants have surpassed the speech comprehension and ability to speak within one year of surgery for children of the same age who were rehabilitated for deafness with hearing aids or using tactile oscillators. The most recent follow-up data indicate that, at least for children who had cochlear implant surgery before the age of 5 to 7, the composite language development indicators, including comprehension, articulation and communication, are not only proportional to his age at implantation, but the indicators for his age at implantation are comparable to those for the natural age of a normal hearing child. Limitations First, there are psychological and social aspects. The maintenance, appearance, and effectiveness of the cochlear implant itself can be psychologically stressful for the user, and the high expectations of the implant recipient or his or her family and friends can also lead to negative effects. For example, current cochlear implants can only help with lip reading for some older prelingually deaf patients, and limit the ability of some patients to enjoy music and understand speech in noise. Because there are no preoperative physiological, psychological, physical or other testing indicators that can predict postoperative outcomes for cochlear implant recipients given current technology, it is important for physicians to help patients consider the various possibilities for success when making preoperative decisions about implantation. Prevention Prevention is the key to ensuring children’s ear health, but not enough is being done in this area, mainly because newborn hearing screening is not yet widespread in a significant number of areas. Only some large cities, such as Beijing, have done a better job. There are two main methods of hearing screening: one is subjective, the hearing screening instrument developed by Peking Union Medical College, the principle is to give the baby some sound stimulation, observe its reflection. The other is more objective and uses the principle of otoacoustic emission, where the ear emits sound while receiving it. A probe is placed in the ear to observe the emission of sound upon hearing it. The Future Cochlear implants will breed breakthroughs in several areas in the future. First, the most pressing issue at hand is to explain and predict the large amount of individual variation in cochlear implants, and in particular, how to predict post-operative outcomes before surgery to reduce the psychological stress of the implant recipient and to have a rational expectation of the outcome of the implant. Second, the design of speech processors will vary from person to person, focusing on how to improve speech recognition in patients with poor outcomes, and how to improve speech recognition in noise and improve the quality of sound, including the enjoyment of music, in patients with good outcomes. Over the next 10 years, the development of large-scale integrated circuits will lead to the miniaturization of cochlear implants. While the current box-type speech processor is being replaced by a behind-the-ear device, the next step is the emergence of fully implantable cochlear implants. A fully implantable cochlear implant may use the patient’s own eardrum as a microphone and use the body’s bioelectricity or an internal buried battery to power the internal voice processor. Through long-term follow-up studies, we will also know whether cochlear implants can help children with prelingual implants fully achieve normal speech and language skills. The answers to these questions will have a profound impact on the study of child language development.