Download Waves Lesson # 6- The ear This lesson will take 2 class periods

Waves
Lesson # 6- The ear
This lesson will take 2 class periods
Time frame: 60 minutes
Vocabulary
Pinna- the visible part of the ear that resides outside of the head
Middle ear- transmits energy from compression waves in the air to fluid–membrane
waves within the cochlea
Cochlea- is filled with a watery liquid, which moves in response to the vibrations coming
from the middle ear. As the fluid moves, thousands of "hair cells" are set in motion, and
convert that motion to electrical signals that are communicated via neurotransmitters to
many thousands of nerve cells.
Ossicles- are the three smallest bones in the human body. They are in the middle ear
and transmit sounds from the air
Eardrum- transmits sound from the air to the ossicles inside the middle ear
The inner ear- the innermost part of the ear, which houses the cochlea and a system
dedicated to balance
Objectives
Students will be able to
1. Understand that the ear is used for both balancing and hearing
2. Understand how the ear senses sound and vibration
3. Create and label an ear
Introduction
Read article“ Your Ears” and take a tour of the ear with your students. Students don’t
have to know all the terms and their functions. They just need to get a general idea.
Concepts
After taking a tour of the ear with students, tell them that the ears do more than just
hearing. They also keep us balanced. In the inner ear, there are three small loops
above the cochlea called the semicircular canals. Like the cochlea, they are also filled
with liquid and have thousands of microscopic hairs.
When you move your head, the liquid in the semicircular canals moves, too. The liquid
moves the tiny hairs, which send a nerve message to your brain about the position of
your head. In less than a second, your brain sends messages to the right muscles so
that you keep your balance.
Focus Activity # 1
Materials:
A cup half filled with water
Shake the cup and them put it on a table. Ask the students what they notice.
The water keeps moving even after you have stopped shaking the cup. Ask the
students how this relates to the ear.
Ask your partner or a student to spin and then after 10-15 seconds stop. Students will
know that after the person stops spinning, he or she will become dizzy and may even
fall. Ask students what they think this has to do with the ear.
* Explain to them that sometimes, the liquid in the semicircular canals keeps moving
after you’ve stopped moving. The water in the cup was still moving around even after
the cup wasn’t moving. The same thing happens when you spin or go on a fast ride in
the park.
When you stop spinning or step off a ride, the fluid in the semicircular canals is still
moving. The hairs inside the canals are sensing movement even though you’re standing
still. That’s why you might feel dizzy- your brain is getting two different messages and is
confused about the position of your head. Once the fluid in the semicircular canal stops
moving, your brain gets the right message and you regain your balance.
Focus Activity # 2- Balance
You may divide students into groups.
Materials:
Ear plugs, anything you can put on your head and balance
Procedure
Instructions to students
1. Before the experiment, ask students what they think would happen if they put
earplugs in their ears and tried to balance on one leg
2. Have students stand on one foot for 30 seconds while holding their left finger on their
noses
3. Plug your ears *ONLY WITH EAR PLUGS and try it again
4. See if they notice a difference
5. Ask them to repeat these step by trying to balance different things on their heads
while standing on one foot with ear plugs.
Focus Activity # 3
Create a crawl through ear with class
Materials and Procedure:
1. Divide students into 3 groups and give each group a bucket with items.
2. One group creates the outer ear, one group creates the middle ear and the other
group creates the inner ear.
3. Use the pop-up play tent as the pinna .
4. Leave one flap open for the hole and the other flap down for the ear drum.
5. Inside, use yellow play-doh as ear wax and brown yarn as hairs.
6. The middle ear, ear canal, is under a table or desk
7. Use an empty 2-liter bottle as the eustachian tube.
8. Use another 2 liter bottle filled with mustard and water to represent the Eustachian
tube filled with mucus when someone's sick. (optional)
9. Use a toy hammer to represent the hammer
10. Use a toy drumstick as the anvil
11. Use the triangle as the stirrup
12. Put a bin of water surrounding the cochlea
13. The cochlea should be made out of a duster, which will be like the hairs, sitting in
water - there is liquid around the cochlea
14. Use jump ropes as the auditory nerves
15. Use pillows for the brain
16. Make labels for each part of the ear as you go
17. Have some students be the brain and have others be sound waves
18. Tell the sound wave students a riddle. Have one student crawl through the ear to tell
someone in the brain.
19. Then tell another student the answer to the riddle. Have that student crawl through
the ear to tell the message to the brain.
Conclusion- Protecting your ears
Talk to students about the importance of protecting their ears. Here are some things
they can do to help protect their ears:
● Keep your ears clean by washing them when you wash your face.
● Don't poke anything into your ear canal - not even a cotton bud.
● Loud noise can damage your hearing. Any noise that makes your ears ring or
feel dull is too loud.
● See your doctor if your ears hurt or they keep feeling blocked up.
● Use sunscreen and a hat to protect the outside and top of your ears when you
are outside in the sun.