Funday Times

The Ear
By Smriti Daniel
Sit still for a moment… what do you hear? Is it the sound of a car passing by? Or your dog barking? Perhaps you can hear your mother laughing? There's always something making a noise isn't there? Sounds are everywhere and you have these two great things that allow you to hear most of them - your ears!

Your ears actually collect sounds. After they've done that, they process them and then send these sound signals to your brain. And that's not all. Your ears also help you maintain your balance. Isn't that weird? We'll take a look into how they do that later. First let's figure out what parts make up your ears.

The ear is made up of three different sections: the outer ear, the middle ear, and the inner ear. These parts all work together as a team to help you hear and process sounds.

The outer or external ear which is also known as the pinna or auricle (say: or-ih-kul) is the part of the ear that you can see when you look in the mirror. When you wear ear rings, you wear them on your earlobe, which is again a part of the pinna. The main job of the outer ear is to hang out there and collect sounds - whether it's the juicy secret your friend is whispering to you or the things that are happening on T.V.

Another part of the outer ear is the ear canal. It is here that wax is produced. Earwax, the yellowy brown sticky thing you find in your ear is in fact the protector of your ear canal. Earwax contains some chemicals that fight off any infections that would dare to hurt sensitive skin in the ear canal. That sticky wax also catches the dirt hanging around, thereby helping to keep the ear canal clean. Quite the knight in disguise isn't it? It may be disgusting, but boy is it useful! That's why all doctors tell you not to use ear buds to take all your wax off - you need it.

Now if we follow the ear canal we end up inside the middle ear. Once the sound waves are caught by the outer ear, they enter the ear canal and travel down it till they make their way into the middle ear. The middle ear has the middle man job of taking these sound waves and converting them into vibrations that have to then be delivered to the inner ear. It does this with the help of a certain part which, sounds like a musical instrument. Can you guess? Well it's the eardrum. It gets its name from the thin piece of skin that forms it - the skin is stretched tight like a drum.

The eardrum is between the outer ear and the middle ear and separates the two. It also separates the outer ear from the ossicles. In case you were wondering the ossicles are the three tiniest, most delicate bones you have in your body. The first one is called the malleus. The malleus is attached to the eardrum and means "hammer" in Latin. The second is the incus, which is attached to the malleus and means "anvil" in Latin. An anvil is a heavy block of iron or steel on which hot metals are shaped by hammering. The stapes, the smallest bone in the body, is attached to the incus and means "stirrup" in Latin. When sound waves reach the eardrum, they cause the eardrum to vibrate. When the eardrum vibrates, it moves the tiny ossicles - from the hammer to the anvil and then to the stirrup. These bones help sound move along on its journey into the inner ear.

Sound comes into the inner ear as vibrations and enters the cochlea (say: ko-klee-uh), a small, curled tube in the inner ear. The cochlea is filled with liquid, which is set into motion, like a wave, when the ossicles vibrate. Now the cochlea is also lined with tiny cells covered in tiny hair that are so small you would need a microscope to see them. Though they are small, they're still very important! When sound reaches the cochlea, the vibrations cause the hair on the cells to move, creating nerve signals that the brain understands as sound. The brain puts it together and, tum tum ti tum- You can now hear your favorite song.

Remember talking about ears helping you keep your balance? Well, they do just that. In the inner ear, there are three small loops above the cochlea called semicircular canals. Just like the cochlea, they are also filled with liquid and have thousands of microscopic hair. When you move your head the liquid in the semicircular canals moves too. This causes the tiny hairs to move, and they in turn 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.

Fascinating isn't it? So why do you feel dizzy? Sometimes the liquid in your semicircular canals keeps moving after you've stopped moving. To understand this, fill a cup halfway with water. Now move the cup around in a circle in front of you, and then stop. Notice how the water keeps swishing around, even after the cup is still? That's what happens in your semicircular canals when you go round and round, or ride a merry go round.

When you stop spinning or step off the ride, the fluid in your 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 canals stops moving, your brain gets the right message and you regain your balance.

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