Sound travels as a wave, producing vibration

The variation in pressure caused by an object’s vibrations push against the surrounding substance – air, for example, and sets up vibrations in the substance – called sound waves. Sound needs a substance to travel through – it cannot travel through a vacuum.

Related articles

• Hearing sound
• Sound on the move
• Measuring sound
• Sound – visualising sound waves

Related videos

• How sound travels under water
• Sound waves in air and water

Related image

• Stars

Related activities

• Modelling waves with slinkies
• Investigating movement and sound with a pūrerehua

Related PLD

• Physics made simple – waves