SSS 2009-04-22
时间：2018-12-24 作者：英语课 分类：Scientific American(四)月
This is Scientific American's 60-Second Science. I'm Karen Hopkin. This will just take a minute.
Just when you thought you’d heard everything, scientists have found that the reason you can hear everything—including things that are very quiet—is because your ears have tiny tubelike motors that mechanically amplify 1 sounds.
You’ve probably heard that it’s the hair cells in your ears that allow you to hear. These cells sport tufts of spiky 2 hairs that are like little molecular 3 mohawks. When sound waves enter the ear these hairs vibrate, and that motion then gets translated into an electrical message that tells your brain that there’s something worth listening to. But the movement of those hairs is not passive, like tall grass swaying in the breeze. The electrical signals they produce feed back on the system, causing the hairs to tilt 4 even more. It’s that so-called “flexo-electric effect” that basically boosts the audio signal and amplifies 5 the sound, findings published in the April 22nd issue of the journal Public Library of Science ONE.
The scientists behind the study also note that the length of the hairs in different species explains why animals like bats can detect such high frequency sounds. It doesn’t, however, explain why your kids can hear their cell phone vibrate two rooms away, yet they never seem to hear a word you say.
Thanks for the minute for Scientific American's 60-Second Science. I'm Karen Hopkin
- The new manager wants to amplify the company.新经理想要扩大公司。
- Please amplify your remarks by giving us some examples.请举例详述你的话。
- Your hairbrush is too spiky for me.你的发刷，我觉得太尖了。
- The spiky handwriting on the airmail envelope from London was obviously hers.发自伦敦的航空信封上的尖长字迹分明是她的。
- The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
- For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。