1. How does a cochlear implant help restore a patient’s hearing? As shown in the diagram below, the cochlear implant system converts everyday sound information into encoded electrical impulses. These electrical impulses stimulate the auditory nerve fibers in the cochlea. The auditory nerve picks up the electrical signals and sends them to the brain. The brain translates these electrical signals into sound. The implant performs continuous stimulation at a very high rate so that the brain can receive sound information without interruption, so that we can hear the sound as soon as it occurs. (1) The microphone of the speech processor collects the sound signals. (2) The speech processor compiles the sound signal into a special pattern of pulses. (3) The impulse signal is transmitted through the skin via a coil to a receiver in the body. (4) The signal is sent to a stimulating electrode in the cochlea and stimulates the auditory nerve fibers. (5) The auditory nerve receives the signal and transmits it to the auditory center, where the brain interprets the sound signal. 2. Are both adults and children suitable for cochlear implants? Which patients with neurological deafness are not suitable for cochlear implants? Cochlear implants are primarily used to treat severe or profound sensorineural deafness in both ears and are available for both adults and children. However, because cochlear implants are designed to restore the function of the cochlea, that is, the ability to convert sound into neural signals that the brain can recognize, the analysis and processing of these signals to form language requires the involvement of the auditory speech center, which only matures with the stimulation of sound speech. If there is no sound speech stimulation before that time, it is difficult for the auditory speech center to mature, which means that even if the cochlear function is restored, it is difficult to develop auditory speech at that time. Therefore, the main factor that determines the suitability of a cochlear implant is not the age, but the timing of the onset of deafness, before (pre-speech) or after (post-speech) language formation, which means that the developmental state and plasticity of the auditory speech center determines the effectiveness of the cochlear implant. In general, children are more suitable for prelingually deaf individuals, and the age of implantation is usually 12 months to 6 years. The younger the age of implantation, the better the results. Due to the risks associated with the procedure, cochlear implants are not recommended for children under 6 months of age, but in cases of meningitis due to the risk of cochlear osseointegration, early surgery is recommended when available. For people with postlingual deafness, hearing aids can be fitted to anyone of any age who has severe or profound sensorineural deafness in both ears and is unable to communicate with normal hearing and speech. Of course, all candidates must have no contraindications to surgery, and the implant recipient and/or guardian must have a proper understanding of the cochlear implant and appropriate expectations. Absolute contraindications include severe malformations of the inner ear (e.g. Michel malformation), absence or disruption of the auditory nerve, acute purulent inflammation of the middle ear mastoid, etc. Relative contraindications include frequent uncontrolled seizures, severe mental, intellectual, behavioral and psychological disorders, and inability to cooperate with auditory speech training. 3.What items should be checked before cochlear implantation? What kind of evaluation should be done before surgery? A detailed medical history and examination by an otologist is required before cochlear implantation. This will help determine whether the cochlear implant is suitable for installation, assess the risks of surgery, and generally determine the effectiveness of post-operative rehabilitation. (1) Routine ear examination, including the auricle, external auditory canal and tympanic membrane. (2) Audiological and vestibular function examinations: pure tone audiometry, acoustic conductance, auditory evoked potentials, otoacoustic emissions, speech audiometry, assessment of hearing aid effects, vestibular function examination (for those with a history of vertigo and who can cooperate with the examination), and electrical stimulation test of the tympanic capsule (if necessary). Patients who do not detect any residual hearing are at a higher risk of poor postoperative auditory rehabilitation. (3) Imaging evaluation: thin-section CT scan of the temporal bone, MRI of the inner ear and cranial brain, and three-dimensional reconstruction of the cochlea if necessary, for detailed understanding of the middle ear, inner ear, and brain. (4) Speech and language ability assessment: For patients with certain language experience or ability, speech and language ability assessment can be done, including speech clarity, comprehension, grammar, expression and communication ability; for infants and toddlers younger than 3 years old who cannot cooperate, “parent-child game” video observation and questionnaires can be used. For infants and toddlers younger than 3 years old who cannot cooperate, video observation and questionnaires can be used. (5) Assessment of children’s psychological, intellectual and learning abilities: For children suspected of having mental retardation or abnormal psychological behavior, further observation, diagnosis and evaluation in professional institutions are recommended. For children with socio-cultural mental retardation, cochlear implantation may be considered; for children with non-socio-cultural mental retardation, ADHD, autism (autism) and other mental retardation, parents should be informed of the difficulties that these disorders may bring to post-operative rehabilitation, and parents should be helped to establish objective and reasonable psychological expectations. (6) Pediatric or internal medicine assessment: perform a general physical examination and relevant auxiliary examinations to understand whether the child can bear the risks associated with surgery. (7) Family and rehabilitation assessment: The patient and/or guardians and teachers should be made aware of the importance of auditory speech rehabilitation after cochlear implantation, and the patient and/or guardians should be helped to establish correct expectations and be prepared for post-operative rehabilitation training and the choice of rehabilitation sites for children with prespeech deafness. 4. Is cochlear implant surgery dangerous? Is cochlear implant surgery minimally invasive? Will it leave scars on the head and neck and affect the aesthetics? Cochlear implant surgery is very mature and safe, and the complication rate is low. Common complications include tympanic membrane perforation, external ear canal damage, abnormal taste, vertigo, tinnitus, facial muscle twitching or pain, infection, scalp hematoma, cerebrospinal fluid leakage, facial nerve palsy, meningitis, intracranial hematoma, body displacement or dislocation of implant, and skin flap necrosis. Cochlear implant surgery is a microsurgery, and the incision is made behind the ear and in the hairline, so it does not affect the aesthetics at all. 5. How do I adjust my cochlear implant? How many times does it need to be adjusted? What should I do if my hearing is still poor or if there is noise after surgery? Usually, the cochlear implant is turned on 1-4 weeks after surgery, and the cochlear implant is usually adjusted 1-2 times within the first month after the cochlear implant is turned on, then the adjustment interval is extended according to the patient’s condition, and finally the cochlear implant is adjusted once a year. The start-up and adjustment methods and procedures can be performed according to the technical requirements of each product. If the contralateral ear can benefit from a hearing aid, it is recommended that the hearing aid be fitted as early as possible. The audiologist should have a good basic knowledge of audiology and cochlear implants and be professionally trained. Tuning of infants and children should be done by an experienced audiologist. If the hearing is still poor after surgery, or if there is noise impact, you should contact your doctor, audiologist or manufacturer’s engineer in time to analyze the specific problem, understand whether it is a problem of equipment, tuning or medical problem, and give targeted solutions. 6. Will my hearing be restored after the cochlear implant is installed? What other rehabilitation training is needed? The cochlear implant converts sound into electrical impulses that stimulate the auditory nerve fibers in the cochlea. The auditory nerve receives the electrical signals and transmits them to the brain. The brain must be trained to correctly recognize and process these signals and to form auditory speech. Therefore, cochlear implant recipients must undergo scientific auditory speech rehabilitation after surgery. Through scientific and effective auditory speech rehabilitation training, children can develop and improve their perceptual listening, discriminative listening and comprehension listening skills, and promote the development of speech comprehension, speech expression and language use. For children, auditory training is the foundation of oral training, which can facilitate the return of deaf children to mainstream society and help develop their intelligence. Auditory training helps deaf children to establish various sound concepts, improve their ability to discriminate between different tones of sound, use their hearing when communicating with others around them, conduct speech training, establish audible speech, and develop listening habits. Hearing training should be conducted daily and should be based on daily life, with the sound source as close as possible to the better hearing ear, and with different means according to age. During rehabilitation, the concept of comprehensive rehabilitation should be adhered to, integrating the five major developmental areas of preschool children, such as health, science, language, art, and society, to promote the overall development of children with cochlear implants. For post-lingual deaf patients, the focus should be on auditory adaptation and speech recognition training. 7. How much does a cochlear implant cost? What is the typical cost of commissioning? Can cochlear implants be used for life? The cost of cochlear implant installation mainly includes the cost of surgery (around 10,000 RMB, different hospitals charge different fees, please consult your specific hospital), the cost of the cochlear implant device (tens to hundreds of thousands of dollars depending on the manufacturer and model), the cost of post-operative rehabilitation (about several thousand dollars per month for institutional training), and the cost of post-operative maintenance (free to hundreds of dollars depending on the manufacturer). Cochlear implants are designed to last a lifetime in theory, but as a high-tech electronic product, upgrades are likely to be inevitable over the course of decades of use.