93 Sound-Low

Sound Written by Robert N. Knight

作者:Robert N。 骑士

What Is Sound? Do you know what sound is? Do you know how it gets from one place to another? Do you know how you hear sound? Read this book to find out.

声音是什么?你知道声音是什么吗? 你知道它是怎么从一个地方到另一个地方的吗? 你知道你是怎么听到声音的吗? 读这本书就能找到答案。

A thin layer of air surrounds Earth. Air is made of tiny particles. Sound moves through these particles to get to your ears. Sound is a kind of energy. Like all energy, sound can move things. It can move the particles that make up air. The particles move back and forth and vibrate when there is sound. What makes the particles vibrate?

地球周围有一层薄薄的空气。 空气是由微粒组成的。 声音通过这些粒子传到你的耳朵。 声音是一种能量。 像所有的能量一样，声音可以移动物体。 它可以移动组成空气的粒子。 当有声音时，粒子会来回移动并振动。 是什么使粒子振动?

Let's think about a bat and ball. If you hit a ball with a bat, they will vibrate. This makes the air around them vibrate. The vibrations move away from the bat and ball as sound energy. Wowser! Sound moves very fast. Sound near the ground can travel at 1,200 kilometers per hour (750 mph.) But it moves more slowly high above Earth because there are fewer air particles.

让我们想象一下球棒和球。 如果你用球棒击球，球就会振动。 这使得它们周围的空气振动。 振动以声音能量的形式远离球棒和球。 老古板!声音传播得很快。 接近地面的声音可以以每小时1200公里(750英里/小时)的速度传播。但它在地球上空移动得更慢，因为那里的空气颗粒更少。

How Do Waves Travel? Sound energy moves through air as a sound wave. In some ways, it is like a water wave moving across water. But sound waves move in all directions. The sound you hear comes to your ears as sound waves.

波浪是如何传播的?声能以声波的形式在空气中传播。 在某些方面，它就像一个水波在水中移动。 但是声波向四面八方传播。 你听到的声音以声波的形式传到你的耳朵里。

A sound wave has two parts. One part has air particles packed closely together. The other part has air particles spread out. One part of the wave always follows the other part in a regular way. Different kinds of sounds make waves that look different.

声波有两部分。 一部分是空气颗粒紧密地挤在一起。 另一部分有空气颗粒扩散。 波的一部分总是以一种规则的方式跟随另一部分。 不同种类的声音会产生不同的波。