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That sounds great! In this movie, you’ll explore sound, a kind of energy we can hear. You'll learn how sound travels in waves and makes things vibrate. Sound can travel to your ear and cause your eardrum to vibrate so you can hear. You'll learn that volume describes how loud or soft a sound is and pitch describes how high or low a sound is. You’ll find out how sound can be blocked or absorbed by objects or even bounce off of things. Watch the movie to learn why you sometimes hear echoes.