Lesson 1

You will also need
a clean flat area to do the projects:

SOUND!

This class is about

What IS sound?

Sounds are

What ARE vibrations?

Does that help? Maybe?

One answer is,
“A rapid back-and-forth movement.”

Let’s create some sound vibrations
to figure this out.

Let’s send some vibrating sounds
out into the air to make
things jump and vibrate at a distance.

cookie
sheet

large spoon

You will need:

coffee can
or metal pot

plastic wrap

sugar
or salt

a large rubber band

Stretch the plastic wrap
over the top of a pot
or coffee can.

Sprinkle sugar
or salt onto
the plastic wrap.

Secure the plastic with the rubber band.

What happens
to the sugar or salt on the
plastic wrap as you bang
the cookie sheet?

Look from
the side
to see
the crystals
jump.

Bang the cookie sheet
with the large metal spoon.

You observed

Vibrations!

Does the loudness of the banging spoon affect the sugar?

Does the result vary as you get closer with the banging?

A rapid
back-and-forth
movement!

The sound vibrations started
when you banged on the cookie sheet.

As the cookie sheet vibrated,
it made the air surrounding it vibrate, too.

The vibrations in the air spread outward.

The vibrating air hit the can
and the plastic wrap.

The sugar jumped
as the plastic wrap vibrated!

Remember:

Sounds are

VIBRATIONS!

Now make a homemade kazoo and feel the

You will need:

a toilet paper tube
or paper towel tube

a small
rubber
band

VIBRATIONS!

scissors

Poke 2-3 holes
toward one end
of the tube.

Wrap a piece of
wax paper around
one end
of the tube.

Secure it with a rubber band.

VIBRATIONS?

Now try the kazoo in your kit.
Get a friend and strike up the band!

Hum a tune into
the open end
of the kazoo.

Put your fingers on the wax paper as you hum.
Do you feel the

Sounds are, indeed,

Vibrating Vocal Cords!

Place your fingers over your vocal cords on your neck.

Speak and
make sounds.

Feel the vibrations!

Sounds
are
vibrations!

You can use a balloon to SEE sound vibrations.

WATCH
the neck
of the
balloon vibrate.

Have an adult help you blow up the balloon
in your kit.

Now make
it squeak
by stretching the neck
of the balloon to release
the air slowly.

The air rushing
through the squeezed
opening makes
sound vibrations.

Ears are vibration detectors!

The visible portion of your ear is
that stiff oddly-shaped structure
on either side of your head.

Select or click on the auditory canal
in the diagram of the ear
(HINT: It is a light green.)

Where is this canal in your ear?

Now click on the outer
visible portion of the ear.

This canal, along with
the visible portion of the ear,
is called the OUTER EAR.

auditory Canal

pinna

The Outer Ear

Click on the tympanic membrane in the diagram.

tympanic membrane
or eardrum

Inside your ear at the end
of the canal is a thin stretch
of tissue called the eardrum
or tympanic membrane.

When sound vibrations reach the tympanic membrane,
it vibrates much as did the plastic wrap on the coffee can or the wax paper on the kazoo.

The Eardrum

Click on the
bone next
to the eardrum
(light blue) called
the malleus
(mal-ee-us).

malleus

Middle Ear

Click on the MIDDLE EAR in the picture. (HINT: It is red.)

The eardrum vibrations cause
the three tiny bones in
your MIDDLE EAR to move.

middle ear

incus

stapes

Click on the
last bone, the smallest bone in your body,
called the stapes
(stay-peas).

Click on the
next tiny bone
in the middle ear
called
the incus
(ink-us).

Click after you found the malleus.

Click after you found the incus.

Inner Ear

cochlea

The primary function of the small bones
in the MIDDLE EAR is to transfer sound vibrations from the AIR (gas),
to the FLUID (liquid) in the cochlea
(koh-klee-uh) located in the INNER EAR.

Click on the cochlea.
It is shaped like the shell of a snail.

The cochlea transforms the vibrations in its fluid
into signals that are sent down the auditory nerve to your brain.
Your brain then interprets these signals as sounds.