62 The Five Senses: Supplemental Guide 2C | I Use My Ears to Hear
Like waves in the ocean, sound waves go up and down as they move.
And just like ocean waves, sound waves make noise as they move. But
unlike ocean waves, sound waves are invisible; you can’t see them. Show image 3A-3: Echo Point
It’s easy for sound waves to go through objects like classroom walls
and your hand.[Point to or touch a wall and your hand.]
But sound waves do not go through everything; sometimes a sound
wave will bounce off an object, like the sides of these cliffs to make
an echo.[Point from one cliff to another to show how an echo travels.]
With your partner, think of two things that sound waves can go
through. Then think of two things that sound waves will bounce off
of. I will call on two partners to share their answers.[Allow thirty seconds for students to talk. Call on two partner pairs to share
their answers.]
An echo is a sound that you hear again when sound waves bounce
off something. So with a loud shout from this cliff, the sound waves
will bounce off the cliffs to make an echo that you will hear.[Point from one cliff to another to show how an echo travels.]
How does sound get in your ear? Show image 3A-4: Ear diagram
Using this picture of the bee, sound waves, ear, and eardrum, tell
your partner how sound gets in your ear.[Allow forty-five seconds for students to talk. Call on one volunteer to come up
to the picture and explain how sound gets in the ear.]
Once the sound waves travel into your ear, they bounce off of your
eardrums.[Using a wavy motion, point from the bee to the eardrum to show how sound
waves travel from outside the ear to the eardrum.]
Your eardrums are inside your ears and, like real drums, when they
get bumped, they vibrate back and forth.