1n daily life, noise is hard to avoid, but what kind of noise will cause harm to our ear health, this is a certain standard
first of all, we should learn from the knowledge of auditory system? Choose hearing protection equipment< 1. Understand noise
what is noise? 1t should be said that all annoying, irritating, people do not want to listen to the voice is the voice. Noise is a kind of sound, which is also produced by the vibration of objects< When we are exposed to noise, we should protect our hearing. There are two ways to measure whether sound damages our ears: frequency and intensity
frequency is the vibration number of sound waves in a second, expressed in Hertz. We can understand frequency as tone. High frequency makes the sound sharp, low frequency makes the sound thick
the intensity of sound is expressed by fractional negative (DB), which represents the pressure or strength of sound wave. 1n daily life, we understand it as volume, some soft, some noisy
when the frequency or intensity of a sound reaches a certain intensity, it becomes a harmful noise to us. The harm intensity of noise to our body also depends on other factors, such as the duration of exposure to noise, the longer the exposure time, the greater the harm< How to choose hearing protection equipment (link: http://www.chinalaobao.com/Html/20087/2008721113938.html )
China’s current noise standards have strict regulations on the allowable noise and the corresponding exposure time, and it is clear that ear protection products should be issued to workers before reaching the standard, so as to ensure the health of workers. There are two most common types of hearing protection: earplugs and earmuffs. The earplug also includes the reuse and discard type; Two. A good hearing protection device, whether it is earplug or earmuff, should have the following characteristics: 12. 1t can filter noise effectively; 3. Feel comfortable when wearing; 4. 1t is easy to use; 5. 1t can be used with other protective equipment, such as safety helmet, mask, helmet, etc
3. Origin and selection of sound insulation earplug (link: http://www.chinalaobao.com/Html/201312/20131217104152.html )
the earliest earplug products were invented in Europe. 1t is said that the fishermen in Scotland used a kind of wax earplug to resist the music of sea fairies. The earliest earplug products also originated in Europe, wax earplug is the most traditional material. 1t can be softened by hand and shaped to fit the ear canal. But the disadvantage is not enough hygiene, wax may also remain in the ear canal, not easy to clean. And wear long ears will have the feeling of pain. Later, due to the continuous research and development of new materials, a flexible material has gradually become the mainstream of making noise earplugs. 1t is a polyvinyl chloride (PVC) foam acoustic earplug with slow resilience. The slow rebound earplug will slowly expand in a few minutes and gradually return to its original shape. The earplug with different specifications and shapes can be molded for different people, which is convenient to wear. But later, the European Union had a new definition of PVC products. They found that PVC compounds contained toxins, which were not suitable for making products close to human body, and banned the use of this material. Therefore, PU material is used to replace PVC in the production of noise proof earplugs abroad
1. 1dentification of good and bad
slow rebound effect: the elasticity is too large to prevent noise. When the ear plug expands, it compresses the skin of the external auditory canal, which can cause ear swelling, earache and other discomfort; 1f the elasticity is too small, it can not be in close contact with the external auditory canal, and the sound insulation effect is reduced. Therefore, we must observe the rebound speed of the earplug, the longer the rebound time, the better the quality
softness: softness has a direct impact on the comfort of wearing earplugs
surface texture: some earplugs are sticky to the touch and will stick to the skin of the ear canal when worn in the ear, so you should avoid buying them as far as possible. The best way to identify is to stick the two earplugs tightly together and then separate them. The faster they separate, the better
in addition, noise proof earplugs may also be a trigger for otitis, because many bacteria will grow more vigorously in warm and humid environment
however, it is generally safe to use noise proof earplugs, but some potential risks that may arise from long-term use must be prevented: when the earplug is inserted, it will cause the pressure of the middle ear to rise, and push the ear drum to cause pain, because the earplug is inserted too deeply. 1n order to avoid this danger, first rub the earplug and insert it into the preset ideal position. When the earplug is fully expanded, it is better not to push it in. And vice versa. When pulling out the earplug, in order to avoid squeezing the eardrum, the earplug should be pulled out slowly instead of forcefully
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