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.

[Illustration: 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