广泛的托福阅读背景知识积累，有助于新托福阅读速度和准确率的提升。托福阅读题材分为自然科学、人文科学、互联网等几大类，如果同学们平时能对这些种类的文章都有所涉猎，托福阅读考试中遇到相关的话题就会有非常熟悉的感觉。下面天道教育给大家提供一篇关于生活中噪音的影响的背景材料，希望能拓宽同学们的阅读面。
　　I'm grad 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 basic 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 here. Sounds up to 80 decibels generally aren't harmful. That's noise like traffic on a busy street. But anything louder than 80 decibels, especially with continuous exposure, may eventually hurt your hearing. Once you are 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's 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 handout, 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.