奇速英语

Headphones are helpful. We use them to listen to music without disturbing others. Many kids use them in school. ____1____ They can cause hearing loss if the volume is too loud. Studies show that one out of every 10 kids in the United States has some hearing loss. The cause is loud noise.

 ____2____ They can only be seen with a microscope. “We call them hair cells,” Jackie Clark said. “They look like hairs standing up.” Clark is a professor at the University of Texas at Dallas. She studies how loud noises affect our ears.

Sound is invisible. But it moves in waves. It makes the hair cells move back and forth. Think of the wind in the leaves. Loud noises can damage these cells.The cells scrape (刮蹭) against the ear. This gets them twisted and bent. ____3____

One sign of hearing loss is tinnitus. ____4____ “It’s like someone is playing a note on the flute for a long time,” Clark says. “There’s no getting rid of it.” And the damage affects more than your ears. It can cause anxiety and stress.

  ____5____ Keep the volume on your headphones low. You should be able to hear sounds around you. And other people shouldn’t hear noise from your headphones. “If I can hear what you’re listening to when you’re wearing your headset,” Clark says, “it’s too loud.”

 

A. It’s a ringing in the ears.

B. What about your headphones?

C. How can you protect your ears?

D. But headphones can be harmful, too.

E. Sounds are measured in units called decibels.

F. There are cells inside the ear that help you hear.

G. And once the cells are damaged, they don’t grow back.