LESSON
14
Reading Selection
Making Sounds with Our Vocal Cords
Crickets chirp, rabbits thump, and birds sing.
Animals make sounds to tell each other things.
Some animals, like dogs, make sounds in their
throats the way people do, although they cannot
speak words or make as many different sounds
as people can.
“But how do people make sounds?” you may
wonder. “How do I make the sounds that I hear
when I talk or sing?”
To make these sounds—to speak, sing, laugh, or
shout—you use your vocal cords. They are in a
place in your throat called your voice box, as
the drawing shows.
You can find your voice box by locating your
Adam’s apple. Your Adam’s apple is a piece of
tissue (cartilage) inside your throat at the front
of your voice box. To find your Adam’s apple,
gently touch the front of your neck at about the
middle of your throat. Your Adam’s apple will
feel like a bump. Do not worry if you cannot
find it. If you can speak, you definitely have a
voice box.
Figure 14-4
Location of the
vocal cords
Voice box (larynx)
Voice cords
Windpipe (trachea)
Lungs
Lesson 14 / Making Sounds with Air and Strings: The Human Vocal Cords
AndersonElizabeth
Saturday, September 7, 2013 1:00:50 PM ET
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LESSON
14
Now look at the drawing again. You will see that
your voice box is at the top of the tube called the
windpipe (trachea). Your windpipe goes down to
your lungs. When you are ready to speak or sing,
you send air from your lungs up your windpipe.
This happens so fast you usually don’t even know
you are doing it. The air moves up your windpipe,
through your voice box, and out of your mouth.
When the air passes between the vocal cords in
your voice box, it makes them vibrate, and you
hear the sound of your voice.
Air also passes between your vocal cords each
time you breathe in or out. But the vocal cords are
open so that they do not vibrate when you are just
breathing. When you want to speak or sing, your
vocal cords tighten up and move closer together.
These two pictures show the difference.
You made a model of your vocal cords today. The
rubber bands in your model stretch like the vocal
cords in your voice box. The rubber bands make
higher sounds when they are stretched tighter,
and your vocal cords make higher sounds when
they are stretched tighter.
Adult women’s vocal cords are about 11 millimeters
(about one-half inch) long. Adult men’s vocal cords
are typically longer. They are about 15 millimeters
(about two-thirds of an inch) long. Adult men
usually have deeper voices than women do. When
a boy is about 12 years old and his voice begins to
change, his vocal cords grow longer and become
thicker. That is what makes his voice sound deeper.
You may have noticed that sometimes your voice
sounds “froggy” or “hoarse.” This happens when
your voice box becomes inflamed or swollen
because you have used your voice a lot or you
were sick. This condition is called laryngitis (lairin-jite-us). The name comes from the word larynx
(lair-inks). Larynx is the scientific name for voice
box. People who have laryngitis usually are able to
speak only in a soft voice. This gives their larynx a
chance to recover.
You may have wondered why your voice sounds
different from your friends’ voices. It has its own
special sound because of the length and thickness
of your vocal cords and the size and shape of your
chest, throat, nose, mouth, and the bones in your
head. No one else’s head and chest are exactly
the same size and shape as yours, so no one else’s
voice sounds just like yours.
Figure 14-5
Muscle
Vocal
cords
Vocal cords open for
breathing
100
AndersonElizabeth
Vocal
cords
Muscle
Vocal cords pulled tighter
for speaking
STC™ / Sound
Saturday, September 7, 2013 1:00:50 PM ET