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I'm glad to see so many of you here. We've become really alarmed over the health center by the number of students we are seeing, who are experiencing hearing loss. First I want to go over some basics about hearing, then we can take a look at our school environment and see if we can figure out some ways to protect hearing. The leading cause of preventable hearing loss is excessive noise. Too much moderate noise for a long time, or some types of intense noise for even a short time can damage hearing. Loudness is measured in units called decibels. One decibel is the lowest sound that the average person can hear. Sounds up to 80 decibels generally aren't harmful, that's noise like traffic on a busy street. But anything louder than 80 decibels, esp. with continuous exposure, may eventually hurt your hearing. Once you're up to around 140 decibels, that's like a jet plane taking off, then you might even feel pain in your ears. And pains are sure sign that your hearing is at risk. Even one exposure to a really loud noise at close range can cause hearing loss. So what you need to do is limit your exposure to harmful levels. If you pass along this hand-out, we can take a look at the decibel level of some common campus sounds. Notice how loud those horns are that people take to football games. They are really dangerous if blown right behind you. Now, let's try to generate a list of damaging noises.
很高兴见到大家。很多到我们健康中心来看病的失聪学生给我们敲想了警钟。首先，我想大致介绍一些听觉方面的基本知识，然后我们考察一下学校的环境，看看能否找到一些保护听觉的办法。过多的噪音是导致失聪的首要原因。长时间听音量适中的噪音，或短时间受到强音的刺激也能损害听力。音量以分贝作为衡量单位。一分贝是指人耳能听到的最小的声音。声量一直达到80分贝对人体都是无害的，比如繁忙街道上的噪音。但是，任何超过80分贝的声音，特别是连续暴露在这种声音之下，终会伤害到听觉。当声音达到140分贝时，就好比喷气机起飞时的声音，你可能会觉得耳朵疼痛。疼痛是听觉处在危险期的标志。甚至在近距离受到强音的刺激也能丧失听力。所以，你们要做的是限制自己暴露在有害的分贝下。如果你们把这分材料传阅一下，就可以看到校园内一些声音的分贝含量。注意橄榄球比赛时，观众吹喇叭时的声音有多大。当他们在你身后吹喇叭时真得很危险。现在，让我们列出一个有害噪音的清单。