Some people have hearing loss or even become deaf, which brings a lot of inconvenience to study and life, and most of the reasons are caused by acquired. If you know the main factors that cause hearing loss, you can avoid them and prevent them before they happen. Drugs: Some common drugs are harmful to hearing. For example, long-term injection of streptomycin or inappropriate application of gentamicin may cause tinnitus and deafness. Erythromycin, aspirin and certain anti-cancer drugs, if hearing problems occur after taking the medication or injection, you should stop the medication and go to the hospital for examination in time. Noise: Noise can reduce the amount of blood flowing through the auditory cells and auditory nerve in the ear, making hearing function impaired, and is an important factor in current environmental pollution. The stronger the noise and the longer the exposure, the heavier the hearing loss and the recovery is quite difficult. Otitis media: This is a common cause of hearing loss in children, so otitis media, especially chronic suppurative otitis media, should be treated actively, and tympanic membrane repair should be performed in time to help restore hearing. Smoking: As smoking can cause poor blood circulation in the ear, hearing can be reduced to varying degrees. Diet: Many hearing loss associated with old age is actually due to atherosclerosis, which causes insufficient blood supply to the inner ear. Medical studies have shown that eating a low-fat diet can help prevent atherosclerosis. In Finland, a long-term follow-up survey of 4,000 people showed that those who controlled their fat over a six-year period had fewer myocardial infarctions and better hearing; those who already had hearing loss also improved. If you need to turn up the volume when listening to the radio or watching TV, often ask for repetition or answer questions when talking to people, as well as the volume of your own speech is very loud, it may be a symbol of poor hearing, and you should go to the hospital in time for examination. Do not wait until the hearing is severely reduced or deaf, then have “awareness”, then often lost the opportunity to treat, so that regret too late.