¹     How do you hear? You hear with your ears. What do you hear? You hear sounds. All sounds are made by vibrations (vi-bra-shuns). Sound waves travel through the air and enter your ears. When the sound waves hit your eardrum, the eardrum vibrates, or moves back and forth. Nerves in your ears send a message to your brain, and your brain tells you what the sound is. Your brain can tell you what sounds you hear even if your eyes are shut!
 
²     Sounds that are close to us are loud. Sounds that are far away are soft. Things that make soft sounds are quiet. A whisper is quiet. A leaf falling to the ground is quiet. Things that make loud sounds are noisy. Trains and airplanes are noisy. Music, sirens, and machines can be loud and noisy when they are close to us, or soft and quiet when they are far away.
 
³     You hear hundreds of sounds every day. Close your eyes for a few seconds. What inside sounds do you hear? Do you hear computers humming, someone talking, or footsteps in the hall? It is fun to listen to outside sounds, too. You may hear cars and trucks, sirens, bells, machines working, and animal sounds. Even though you hear hundreds of sounds every day, your brain helps to filter out sounds that are not so important, or sounds that are mostly noise. So, the next time you want to hear something special, just listen to the sounds around you.