What is this passage talking about?

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 8O decibels generally aren’t harmful. That’s noise like traffic on a busy street. But any- thing louder than 80 decibels may eventually hurt your hearing. Once sounds are up to around 140 decibels, that’s like a jet plane taking off, then you might 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.