This excavator is part of a noisy construction site Animals make sounds So do machines The wind blowing through trees makes a sound What causes sound Sound begins when an object moves back and forth very quickly The movements are called vibrations 5
try this Loop a rubber band around your thumbs Pluck the rubber band with your pinkie finger This makes a sound Watch the band You can see it vibrate The vibrations move through the air to your ears Then you hear the sound You hear a sound when you pluck a rubber band with your finger 6
You can feel vibrations too Put one hand on top of your head and hum loudly The tingling feeling in your hand is from the vibrations you make when you hum You can feel vibrations when you hum 7
