Sound comes from vibration
Every sound you hear starts with a vibration. A vibration is a very fast back-and-forth movement. When something vibrates, it makes the air around it move, and this carries the sound to your ears.
Key idea
Sound is made by vibrations. No vibration means no sound.
How sound travels
Sound needs a material to travel through, such as air, water or a solid. It cannot travel through empty space. Sound travels as it passes the vibration from one part of the material to the next until it reaches your ear.
- Pluck a guitar string — you can see and feel it vibrate.
- Bang a drum — the drum skin vibrates and makes a loud sound.
- Talk with your hand on your throat — you feel it vibrate.
Example
Put rice grains on a drum, then bang the drum. The grains jump up and down because the drum is vibrating.
Remember
- Sound is made by vibrations.
- Sound travels through solids, liquids and gases, but not through empty space.