How Do Noise-Canceling Headphones Work?

What scientific principle do noise-canceling headphones use to reduce sound?

• Constructive interference

• Destructive interference

• Sound absorption

• Sound reflection

What are sound waves made up of as they move through the air?

• Light and shadow

• Heat and cold

• Compressions and expansions

• Vibrations and echoes

When two sound waves combine through destructive interference, what happens to the air?

• The air becomes hotter.

• The air vibrates more intensely.

• The air is neither compressed nor stretched.

• The air becomes colder.

What type of noise do noise-canceling headphones work best on?

• Sudden, loud noises

• Noises that change pitch frequently

• Constant, droning noises

• Very high-pitched sounds