山东省临沂市中考英语阅读理解真题汇编(精选 2017-2019年真题 +详细解析答案，值得下载 ) 2019 三、阅读理解。 (共 25 小题，计 25 分) A (2019 山东临沂 )Do you often listen to music at loud volumes ( 音量)? You should know that this habit is bad for your hearing. Over 1 billion young people are at risk of hearing loss (听力丧失 ) ,because of listening to loud noise for long periods of time. Listening to music or watching a TV show at loud volumes can harm your hearing. The United Nations has standards for safe listening. It is not safe to listen to sounds that are louder than 85 dB ( 分贝 ) for eight hours or 100 dB for 15 minutes. The sound of a busy road is about 85 dB and the sound of a rock concert can be about 100 dB. Loud noise is harmful to the inner 二 Most of us are bon with about 16,000 hair cells ( 听毛细胞 ) in our inner ears. These cells notice sounds. However, listening to loud noise for a long time can make these cells work too hard and cause some of them to die. This is what causes hearing loss. Once this happens, it's hard to get your hearing back. Some people might think that their music isn't all that loud. But this can depend on where you are. For example, if you are in a noisy place like the subway, you might turn up your music too loud without realizing it. Later, when you listen to it at the same volume in a quiet place, you alight feel uncomfortable The "safe level" for most sound is below 80 dB for up to 40 hours a week. A level of 80 dB is about equal to (相当于 ) the noise of a subway. Here is some advice on safe listening. Over-the-ear headphones (头戴式耳机 ) are better than in-ear ones. They do a better job of stopping outside nois...
