Each use of headphones should not exceed 1 hour, long-term use, or even cause irreversible damage, leading to noise deafness, this hearing loss is often not easy to detect, but also not easy to treat. Symptoms of noise-related tinnitus: 1. Tinnitus Appears early and presents a persistent high-pitched sound in both ears. 2. Hearing loss is slowly progressive, at first it is unconscious because it is mild and can be fully recovered or only involves high frequencies; later it is detected when it involves speech frequencies. 3, long-term exposure to strong noise environment, but also can cause the cerebral cortex, sympathetic nervous system, heart, endocrine and digestive system and other tissues and organs of functional disorders. 4. Ear examination of the tympanic membrane is mostly abnormal. Pure tone audiometry shows sensorineural deafness; the typical curve in the early stage is 4000Hz “V” type decline; later the neighboring frequencies are involved, the curve is “U” type; the curve in the late stage is declining. The hearing impairment progresses from high frequency to speech frequency and gradually worsens, but rarely develops into total deafness. Noise deafness is mostly bilateral symmetry, if there is a difference, it may be related to the direction of the sound source, body position and original ear disease. So try to listen to music with headphones for a long time, especially built-in headphones!