Hearing and language are important means for human beings to communicate with each other and understand the world. Hearing loss occurs in different degrees due to hearing dysfunction caused by lesions in any part of the auditory pathway and is called deafness. According to the estimation of World Health Organization, there are nearly 600 million people with mild hearing loss in the world, and 20.57 million people with hearing impairment in China, accounting for 24.16% of the total disabled population, ranking the first among all kinds of disabilities, hearing impairment is becoming an important factor affecting public health and quality of life. Hearing loss can be caused by mechanical blockage of sound conduction in the outer or middle ear (conductive deafness) or by damage to the inner ear, auditory nerve, or auditory center (sensorineural deafness). The common causes of conductive deafness include inflammation of the external ear, cerumen embolism in the external ear canal, congenital ear malformation, narrowing or atresia of the external ear canal, tympanic membrane perforation, purulent otitis media, mastoiditis, and cholesteatoma of the middle ear. The more common causes of sensorineural deafness are: 1. hereditary deafness: such as Refusum’s disease, which is a familial genetic disease. 2. 2. Congenital deafness: low birth weight or prematurity, mumps, meningitis, measles, and rubella virus in the mother’s pregnancy can lead to hearing nerve damage in children. 3.Age-related deafness: an age-related degenerative disease, often complaining that others speak ambiguously or cannot understand what others mean. 4.Noise deafness: Long-term exposure to strong noise (such as factories, foundries, railroad shunting yards) or one-time exposure to extremely strong impulse noise (such as firecrackers, gunfire, explosions, etc.) can cause permanent damage to the cochlea in severe cases. 5.Ménière’s disease: an inner ear disease with vertigo. 6.Ototoxic deafness: Some drugs such as aminoglycoside antimicrobials, aspirin and certain antineoplastic drugs can injure the cochlear auditory nervous system when used in large doses, leading to hearing loss. 7, sudden deafness: an unexplained sudden hearing loss, 1 to 2 days can reach the peak of deafness or even total deafness. 8.Auditory neuroma. 9. Otosclerosis: It is the most common cause of slowly progressive transonic deafness in adults with normal tympanic membranes and manifests as sensorineural deafness when a bony lesion is adjacent to the cochlear canal. Hearing rehabilitation of deafness can be considered from the following aspects: 1. Medication and other conservative treatment methods: such as acute otitis media, otitis externa, cerumen embolism in the ear canal and early sudden deafness. In particular, once sudden deafness occurs, it needs to be treated with medication as early as possible, and the earlier the treatment, the better the prognosis. Those who have high risk factors for noise deafness should pay attention to noise protection. 2. Surgery: Surgery can reconstruct the outer and middle ear sound-transmitting structures and remove the lesions. For example, most chronic otitis media, auditory neuroma, otosclerosis, etc. 3.Wearing hearing aids: For patients whose medication and surgical treatment do not work, wearing hearing aids is a good choice. Hearing aid is a kind of sound amplification device, through which the sound is amplified and transmitted to the ear, so that people with hearing loss can be compensated for their hearing. But wearing a hearing aid is a learning curve, and you can’t just go out and buy one and wear it. Just like eyeglasses, hearing aids also need to be tested. Our speech is made up of different frequencies of sound, and deaf people have different hearing loss at different frequencies. Otherwise, you will “hear loud sounds without knowing what people are saying” or “hear harsh and unbearable sounds”. There are many types of hearing aids, such as cassette hearing aids, behind-the-ear hearing aids, and canal hearing aids. For patients with severe conductive deafness or external atresia, a bone-anchored hearing aid (also known as BAHA), which is a hearing aid device surgically implanted into the surface of the skull to allow sound to be transmitted directly into the inner ear via bone conduction, may be required. 4. Cochlear implantation or brainstem implantation: Patients with sensorineural deafness with bilateral profound deafness and total deafness may be considered for cochlear implantation or brainstem implantation depending on professional examination results.