Sound, Waves, and Communication
What is a wave?
Wave basics
A wave is a pattern that transfers energy from one place to another without moving matter very far overall. Waves can travel through air, water, or solid materials. Sound is a wave made by vibrations.
Sound needs matter
Sound cannot travel through empty space because it needs particles to pass vibrations along.
How sound works
When something vibrates, it makes nearby air particles vibrate too. Those vibrations travel to your ears, and your brain interprets them as sound. Louder sounds have larger vibrations; higher-pitched sounds usually vibrate faster.
Sound terms
Why can sound not travel in space?
Sound needs particles, and space has almost none.
Correct answer: There are no particles to carry the vibrations
Wave examples
Sound waves
- Need a material medium
- Carry vibrations
- Used in speech and music
Light waves
- Can travel through space
- Carry energy from the Sun
- Let us see objects
What makes a sound louder?
Larger vibrations usually produce louder sound.
Correct answer: Larger vibrations
How your ear helps you hear
-
1
Step 1: Sound waves enter the ear
-
2
Step 2: They make the eardrum vibrate
-
3
Step 3: Tiny bones pass the vibration onward
-
4
Step 4: The brain interprets the signals as sound
What is an echo?
An echo is reflected sound.
Correct answer: A sound that bounces back after hitting a surface.