Ask your partner to stand half the distance across the room from you and whisper a sentence to you.

Blow up a balloon and tie the end. The air in the balloon is squeezed or compacted. Hold the balloon against your ear. Ask your partner to whisper a sentence to you again.

Trade places and repeat the experiment.

Did the balloon change the sound of your partner's whisper? How and why?

Does air or compacted air transmit sound better?

The air in the balloon is under greater pressure than the surrounding air. Since the air in the balloon is denser than the surrounding air, sound travels better through the balloon.