This lesson will introduce young people to the structure of their ears and how they work through a diagram and by building a model ear drum. The youth will play a listening game to learn more about their hearing and how important it is to keep their ears healthy.
Describe the three basic parts of the ear, using the Your Ears Handout as a visual guide (see What You Need). Discuss the care of each part.
Outer ear: This is the part you can see. The outer ear is where sounds are collected and moved along the ear canal toward the middle ear. The middle ear is separated from the outer ear by the eardrum.
Middle ear: Vibrations from the eardrum travel through the little bones of the middle ear (ossicles) and are sent to the inner ear. The space in the middle ear is filled with air.
Inner ear: This is where the vibrations from the middle ear create nerve signals. The nerve signals send the messages to your brain that become the sounds you hear.
Outer ear: This is the only part you should clean.You can wash behind your ears and around the outside. Sometimes shampoo or soap can get stuck behind them so rinse well!
Whatever you do, don’t stick anything larger than your elbow into your ear. Even though earwax can seem kind of icky, it is normal and usually healthy. It should only be cleaned out if your doctor says it’s OK.
If you have pierced ears, be sure to keep them clean with a sterile solution or they can become infected.
Middle ear: This part can become infected. If this happens, your doctor can prescribe a medicine (such as an antibiotic) to help treat the problem.
You should never stick anything in your ear canal because the eardrum can be punctured or torn.
Inner ear: The part can also become infected and would need treatment by your doctor.
Give each young person or small group about 10 grains of rice or salt. This is just a visual aid to help them see what is happening to the “eardrum” (plastic wrap) when exposed to loud noises.
Tell the youth to stretch the plastic wrap tightly over the cup, secure it, and place the grains of rice or salt on top. They now have model eardrums.
Have the young people experiment with noisemakers to see if they can get their model eardrums to vibrate. They will know if it is working because the rice or salt will bounce around. This is a simulation of what happens when sound waves reach your eardrums. They vibrate, causing other parts of your ears to vibrate, sending signals to your brain that are processed as sounds.
After a while ask for volunteers willing to make small holes in their model eardrums. Experiment with that for a while. Notice what happens. Compare those with tears to those still intact. Also compare different size tears.
Discuss the experiment: What did you notice about what happened when we exposed our “eardrums” to different sounds? What happens if we poke a hole or make a tear in one of them? Does it work as well? (No, it does not; it doesn’t vibrate as much. Also, things like the grains of rice or salt can get through.) Try to imagine a hole or a tear in your own eardrum. What do you think would happen to your hearing? What about the health of your ear? (You could have temporary hearing loss or, if the tear didn’t heal, permanent hearing loss. Also, bacteria and other contaminants could get in and lead to infection.) It’s important to remember to never stick anything in your ear to clean it or for any other reason. Doctors are the only people who should put anything in your ears…they know how to do it and can do it without damage.
After the activity, ask the young people to reflect with the following questions:
Conclude the lesson with the following discussion questions.
How important is it that we take good care of our ears? Why? (We function best when they are both working. They are sensitive and can be damaged.)
Besides keeping them clean, what can we do to protect our ears? (Wear a helmet when riding a bike or board or playing contact sports. Avoid loud noises, especially over long periods of time such as a rock concert. A good rule of thumb is that if you have to shout to hear or be heard it’s too loud. Wear earplugs if doing loud work or being in loud environments.)