Cochlear implants, also known as cochlear implants, are artificial devices that replace the function of the cochlear apparatus in the inner ear, convert external sound energy into electrical energy, encode and process it into an appropriate electrical signal, and then send it to the auditory nerve fibers, so that patients with sensorineural deafness can regain their sense of sound. Cochlear implants can be divided into two types according to the way they are coupled to the inside and outside of the body: transdermal socket type and transdermal inductive coupling type. Deafness caused by the outer and middle ears is called conductive deafness and is usually treated surgically or with hearing aids to restore hearing to the patient. The cochlear implant consists of two parts: the in-ear and the out-ear. The in-ear part is surgically implanted between the muscle behind the ear and the temporal bone. The surgery usually takes 2 to 3 hours. It takes 7 to 10 days for the wound to heal after surgery. One month after the post-operative injury, the patient returns to the hospital to be fitted and adjusted to the external device. Specialists and audiologists will activate the computer program inside the speech processor and tune the program in the speech processor according to the patient’s level of comfort with the sound he/she is hearing. The patient needs to come to the hospital regularly to have the speech processor adjusted to the sounds he or she will hear after the implant. At the same time, the patient has to undergo hearing and speech rehabilitation. For patients with post-speech deafness, the training usually takes a few months, while for patients with pre-speech deafness, it takes 2 to 3 years of rehabilitation to achieve the desired results.