The Five Senses: Supplemental Guide 2A | I Use My Ears to Hear 51
An echo is a sound that you hear again when sound waves bounce
off something. So with a good, loud shout from this cliff, the sound
waves from your voice bounce off the surrounding cliffs.
[Point from one cliff to another to show how an echo travels.]
A second or two later, you hear your voice echo very clearly, copying
everything you said. Raise your hand if you’ve ever heard your voice
echo.
So how does sound get in your ear?
Show image 3A-4: Ear diagram
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.
[If available, demonstrate how a real drum vibrates when hit. Allow a few
students to try hitting the drum to feel the vibration.]
When these vibrations move from your ear to your brain, your brain
can figure out what sound made the vibrations.
[Point from the eardrum to where the brain would be located.]
Your brain can also figure out if the sound is loud or quiet, and if it’s
high or low.
Show image 3A-5: Red fire alarm
One way to talk about a sound is to tell how loud or quiet it is.
This is called the volume. Say the word volume with me.
A whisper is a quiet or soft sound and has a low or soft volume.
Whisper something to your partner.
A fire alarm is a loud sound and has a high or loud volume. Can you
mimic the sound of a fire alarm?
A fire alarm is supposed to be really loud so people can hear it clearly.
The loud volume of the fire alarm makes you want to run away from
it. This is one way your sense of hearing helps to protect you.