Sound

Key Notes:

What is Sound?

• Sound is something we hear.
• It is a form of energy that travels in waves.

How is Sound Made?

• Sound is made when something vibrates (shakes back and forth).
• These vibrations move through the air and reach our ears.

Sources of Sound

• Things that make sound are called sound sources.
• Examples: Drums, bells, people talking, animals, machines.

How Does Sound Travel?

• Sound travels through air, water, and solid materials.
• It cannot travel through a vacuum (where there is no air).

Loud and Soft Sounds

• Loud sound: More energy, strong vibrations (e.g., thunder).
• Soft sound: Less energy, gentle vibrations (e.g., whisper).

High and Low Pitch

• Pitch means how high or low a sound is.
• A whistle has a high pitch; a drum has a low pitch.

Ears Help Us Hear

• Our ears catch sound waves and send signals to the brain.

Good and Bad Sounds

• Pleasant sounds: Music, birds singing.
• Unpleasant sounds: Noise (too loud or disturbing).

Controlling Sound

• We can make sound louder or softer, or block it with materials like cotton or curtains.

Fun Fact

• Bats use echoes to find their way in the dark — this is called echolocation!