The external sound reaches the inner ear in two ways. One is the air conduction path through the external auditory canal, tympanic membrane, ossicular chain and vestibular window, and the other is the bone conduction path in which the skull moves and compresses to directly fluctuate the external lymph. When the sound is introduced into the inner ear, the hair cells on the basilar membrane of the cochlea are sheared to produce action potentials, and the electrical signals are introduced into the brain with the nerves to produce hearing. If any of the above links are diseased, hearing will be affected. In medicine, hearing loss is generally called deafness. Deafness does not mean that you can't hear a sound, but there are some differences, including light, medium, heavy and even total deafness. Usually we divide deafness into three types according to the lesion site: auditory deafness, sensorineural deafness and mixed deafness: 1. Acoustic deafness refers to hearing loss caused by the failure of sound transmission transformer, which affects the propagation of sound waves. The sound transmission of human ear is mainly air transmission, so the hearing loss caused by the pathological changes of external auditory canal, tympanic membrane and ossicular chain is acoustic deafness. The pathological changes that can cause acoustic deafness mainly include the following situations: (1) cerumen embolism: cerumen blocks the external auditory canal, hinders sound transmission and causes hearing loss. (2) Tympanic membrane perforation: After tympanic membrane perforation, sound waves enter the deep part of the external auditory canal, and then energy leaks, resulting in hearing loss. Just like a hammered drum, the sound is definitely not as good as the complete drum surface. (3) Tympanic membrane invagination: It is mostly the result of abnormal eustachian tube function. Tympanic membrane invagination increases tympanic membrane tension, changes vibration frequency with sound waves, and affects sound propagation. (4) Secretory otitis media: It is a non-suppurative inflammatory disease in the middle ear cavity. Because there is effusion in the tympanic cavity, it affects sound transmission and reduces hearing. Like a drum filled with water, the sound is depressed. (5) suppurative otitis media: Both acute and chronic suppurative otitis media can affect hearing, mainly due to tympanic secretion blockage or tympanic membrane perforation. (6) Interruption of ossicular chain: middle ear trauma shock or otitis media corrodes the ossicular chain, which leads to joint dislocation. After otitis media, the ossicular chain adheres and is fixed in the tympanum, which reduces the amplification effect and affects hearing. (7) Tympanic sclerosis: Various inflammatory diseases can cause calcium deposition in the tympanic structure, and its function is limited, thus affecting sound transmission. Hearing deafness generally does not lead to complete hearing loss. If you do pure tone hearing test, you can find that the air-conduction hearing loss is generally less than 60 decibels, which belongs to moderate deafness, while the bone-conduction hearing is basically within the normal range. 2, sensorineural deafness: It refers to the pathological changes of hair cells, auditory nerves and auditory pathways at all levels in the ear spiral organ, which makes the sound perception and nerve impulse conduction disorder, causing sensorineural deafness. The common diseases are as follows: (1) Otosclerosis: Unlike tympanosclerosis, Otosclerosis is a disease with unknown etiology. It is a disease that the dense bone plate of the inner ear is replaced by spongy new bone, which is the same as that the wall of the house is replaced by jerry-built sand, but the osteoporosis of the ear is only the first stage of this disease. It will develop further afterwards. There is a lot of fibrous tissue hyperplasia and calcification in bones, just like cement placed in the open air. It will soon harden. This stage is also called sclerosis stage, so it is called otosclerosis. The consequence of otosclerosis is the structural change of the inner ear, the deformation and necrosis of nerve cells, and finally the hearing loss, mostly bilateral, which continues to worsen. Hearing loss is mostly perceptual. (2) Meniere's disease: It is a disease with paroxysmal vertigo, fluctuating deafness, tinnitus and fullness in the ear, which is caused by labyrinthine edema of the inner eardrum. Generally caused by one ear, more common in young people. (3) congenital deafness: It can be caused by genetic factors, virus infection or other injuries during pregnancy, and the hearing of the fetus is decreased after birth. (4) Senile deafness: It is caused by the deterioration of hearing organs in the process of human aging, so it is often found that the hearing of the elderly is not as good as that of the young. (5) Deafness caused by infectious diseases: All kinds of acute and chronic infectious diseases can cause sensorineural deafness. Such as polio, diphtheria, typhoid fever and so on. , but it is very rare now. (6) Deafness caused by other systemic diseases: hypertension and arteriosclerosis are the most common. The reason is that the nutrition and blood supply to the inner ear are blocked. Others such as diabetes and hypothyroidism can also lead to hearing loss. (7) Drug-induced deafness: It has been confirmed that aminoglycoside antibiotics such as streptomycin, gentamicin and amikacin can damage human ears and cause sensorineural deafness. (8) Traumatic deafness: brain trauma leads to labyrinth concussion and skull base fracture, which can damage the inner ear and cause hearing loss. (9) Sudden deafness: It is a sudden deafness, which may be related to the blood supply disorder of the inner ear and viral infection. There are many reasons for sensorineural deafness. According to the lesion site, sensorineural deafness can be divided into sensorineural deafness and sensorineural deafness. Sensory deafness is hearing loss caused by hair cell disease. Neurogenic deafness is hearing loss caused by pathological changes of auditory nerve and conduction pathway. 3. Mixed deafness: refers to hearing loss caused by a mixture of sound-transmitting and sound-sensing lesions. For example, people suffering from chronic suppurative otitis media for a long time have both auditory deafness caused by perforation of tympanic membrane and damage of ossicles, and sensorineural deafness caused by long-term absorption of bacterial toxins. This is about connection: tinnitus is an "unpleasant" sound sensation without external sound stimulation, which is mostly manifested as buzzing, clicking and squeaking, occurring in one ear or both ears (cracks). People aged 40-70 are more common, with more men than women. Because tinnitus seriously affects the quality of life, there may be physiological, psychological and social behavior abnormalities, and tinnitus is often accompanied by hearing loss. Therefore, tinnitus should be treated as soon as possible, which can not only obviously relieve or even disappear tinnitus, but also delay hearing loss. At present, there is no single and specific treatment for this. The treatment of tinnitus requires more than two kinds of treatment methods at the same time, and long-term treatment is needed to receive satisfactory treatment results. 1. Tinnitus masking: White noise matched with the tone intensity of tinnitus is given through headphones to mask the tinnitus sound, which can not only divert the patient's attention to tinnitus, but also fatigue the abnormal discharge nerve that produces tinnitus frequency, thus achieving the purpose of treating tinnitus. 2. Hearing AIDS If tinnitus is accompanied by hearing loss, choosing a masking hearing aid can improve hearing and mask tinnitus. But the volume of the hearing aid should be adjusted to a suitable position, not too high, otherwise it may aggravate tinnitus. 3. Biofeedback is a relaxation technique, which allows patients to control some autonomous body functions, such as pulse, muscle tension and brain wave activity, with the aim of improving patients' adaptability to their life activities. 4. Cognitive therapy can change patients' feelings about tinnitus, and it will get good results with masking or drug treatment. 5. Use of anti-anxiety drugs, such as alprazolam; Antidepressants such as nortriptyline; Antihistamines; Anticonvulsants and even anesthetics, such as lidocaine, can be used to treat tinnitus and achieve certain results. Injection of dexamethasone into the middle ear also has a good effect on patients with tinnitus, hearing loss and dizziness. 6. Tinnitus retraining therapy gives patients a low-loudness, stable background sound, which makes patients gradually familiar with their tinnitus sound, 8 hours a day. This method will last 1 ~ 2 years. In addition, there are acupuncture, hyperbaric oxygen, electrical stimulation, surgery, cochlear implant and so on. These treatments need to be carried out selectively under the guidance of doctors. We also need to take the following measures to avoid tinnitus: don't listen to the walkman with earplugs for a long time; The effective way to avoid environmental noise is to wear earplugs away from noise sources or in noisy environments, which can reduce the sound 15 ~ 20 decibels; Stop using ototoxic drugs immediately when tinnitus occurs; Control blood pressure in the normal range; Reduce salt intake; Do not use irritating drinks, such as coffee, tea, cola and chocolate, and quit smoking; Improve blood circulation through more exercise; Correct and treat oral diseases in time, such as malocclusion; Appropriate supplementation of zinc-containing preparations in the elderly is helpful to prevent tinnitus.