6.
阅读理解
Every day, we live with different noises. But how much do you know
about them?
What Is Noise
When sound are loud and annoying, we usually call them noise. Very
loud noise can be bad for our ears and make us sick.
Scientists use decibels (分贝)to tell how loud
a sound is. Sounds louder than 85 decibels can hurt(伤害)
people's ears.
A Good Noise
Not all noises are bad. White noise is a good kind of noise to some
people. It helps them sleep well and feel relaxed. Here are some examples of
white noise: rainfall, ocean waves, and wind blowing.
No Sound, No Good
When you are in a very quiet place, you can hear very quiet sounds.
If all you can hear is your own breathing(呼吸) and
heartbeat, you will not feel well. Most people can't spend over 45 minutes in
places that are very quiet.