091 VOCAL CHORDS AND SOUND PRODUCTION

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091 VOCAL CHORDS AND SOUND PRODUCTION
One of the interesting things to do with a
balloon is to squeak it. A balloon can be used
to teach about vocal cords and sound
production This is very similar to the way we use
our vocal cords to speak.
MATERIAL REQUIRED
Balloons
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Blow up a balloon and hold the mouth of the
balloon in both hands. Stretch the mouth of the
balloon , pinching your fingers on the balloon
while pulling them apart (See picture below)
As the air flows out of the balloon, you can hear
a high-pitched, loud squeaking noise. When you
adjust the tension on the balloon mouth the
pitch and volume of the squeaking changes.
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Why does a balloon squeak when you stretch the
mouth? Stretching the mouth of the balloon makes
a very tiny space for the air to flow out of the
balloon. The air pressure of the balloon itself
forces the air out the mouth, but because of the
stretching, that space is limited. This airflow
causes the balloon mouth (the stretched part) to
vibrate and this vibration makes the noise. Place
your hand on your upper neck , under your jaw and
hum. Youll be able to feel a vibration, similar
to the vibration at the mouth of the balloon.
This is the air being forced over your
tightly-stretched vocal cords.
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Remember how tightening or loosening the balloon
mouth changed the sound of the squeaking? Hum
in a high pitch and feel your neck. Hum in a low
pitch, and the vibration will change.