Chapter 7 HEARING AND LISTENING

Now you are all ready to go to work. What are you going to work with? Books? pencils? paper? Yes, but you have something better than those and all ready for use. It is that little kit of tools that are sometimes called our "Five Senses." You remember that we have already talked about one of them, the sense of touch in the skin. Now which one are you going to use first this morning? If your teacher talks to you, I hope it will be the one we call the sense of hearing. Suppose we try to find out something about this sense of hearing, and begin with a little experiment.

Take a piece of cork in your hand and lift it up high and then let it drop into a large basin or tub of water. What happens? The cork strikes and then goes bob-bob-bobbing up and down on its own waves. Now watch the little waves all around the cork. Where do they stop? They don't stop until they touch the edge of the pan; and no matter how big the pan is, the waves go on and on until they reach the edge.

We can see these waves of water, and so we easily believe that they are there. Now there are, just as truly, waves of air all around us. We cannot see the waves, because they are too small and roll too quickly. But some of these, when they roll against our ears, make us hear. They make what we call sound. You have heard about sending messages through the air, without telegraph wires. Wireless messages are often sent to ships out in the middle of the ocean. This is done by starting tiny electric waves, which travel through the air much as the waves of water are traveling across the ocean beneath. Of course there must be a machine, called a receiver, to catch the waves and "hear" the message.

Mother Nature has given each of you two very delicate little receivers to catch the sound waves and carry them to your brain. You know what they are-you can name them. But how are these wonderful little machines made?

You have never seen the whole of your ear. The part on the outside of the head, of course, you can easily see and feel. Sometimes you notice a deaf person put his hand behind his ear and press it forward so as to catch the sound waves better. These waves roll in at the little hole you can see, and travel along a short passage till they come to a round drum, a piece of very thin skin stretched tight like a drumhead.

Have you ever beaten a drum with a stick? You felt the drumhead quiver under the blow, did you not? Well, when the sound waves beat against the drum in the ear, it quivers and starts little waves inside the ear. Each little wave in turn beats against a little bone called the hammer; the hammer beats against another called the anvil, and this against a third called the stirrup; and the quiver of the stirrup is passed on to a little window, opening into a little room with a spiral key-board; and from this, the wave travels along a nerve to the brain. As the waves reach the brain, the brain hears. In this way we hear all sorts of sounds, from the tick of a watch to the whistle of a train.

THE WAY BY WHICH SOUND WAVES REACH THE BRAIN

A section through the right ear.

There is a sensible old saying, "Never put anything smaller than your elbow into the inner part of your ear." Now, of course, you can't put your elbow into such a tiny hole! So the old saying means, never put anything in. The eardrum is very thin and can easily be broken. Even a slap on the ear, or a loud sound too close to it, might crack and spoil the drum and make one deaf.

The outside ear needs careful washing; there are so many little creases that gather dirt and dust. The deep crease behind the ear, too, will become sore if it is not kept clean.

Besides cleaning your ears, you must train them to listen. Some boys and girls hear just a word or two of what is said, and then guess at the rest and think they are listening, or else ask to have it repeated. We should try to hear exactly what is said; and if we listen carefully, it will soon be much easier to understand at once.

Of course, if you really cannot hear, the doctor can tell you what is the matter, and usually can help you very much. Sometimes people become deaf simply because the throat is swollen. Indeed, most deafness comes from colds and catarrhs and other inflammations of the nose and throat. These spread to the ear through a little tube that runs up to the drum cavity from the back of the throat. Sometimes, when you are blowing your nose, you may feel your ear go "pop"; and that means that you have blown air up into the ear through this little tube. Be sure to see a doctor if you don't hear well; and be sure, too, to tell your teacher, so that she may know why it is you do not hear what she says, and ask her to give you a seat near her, so that you can hear.

Then, too, you should learn to notice outdoor sounds-the songs of the birds, the noises that the animals make, the wind in the trees, and the patter of the rain. The old Norsemen have a story that their god Heimdall had such keen ears that he could hear the grass growing in the meadow and the wool growing on the backs of the sheep! Your ears can never be so keen as that; but there are many, many happy outdoor sounds that you should listen for. They will help to make you happy, too.

Careful listening may sometime save your life. You can hear the car or the train coming, and you can learn to tell from which direction a sound comes. You can learn to tell one sound from another in the midst of many sounds. In more ways than you can think of now, this habit of listening will protect you from danger.

The Germans have a proverb, "Hear much and say little." What does it mean?

"DO YOU HEAR IT? CAN YOU SEE IT?"