Title:	Location	K-4	5-8	9-12	Description	Discipline
Workshop II – Making Sound	Kitchen	X	X	-	Build instruments and learn about sound.

This workshop is geared towards groups of 3-5 with the targeted age for children ranging from 7 to 12 years old.

Materials Required:

• balloons
• 4" cups - 3" cups
• rubber bands - two sizes
• straws - two sizes, one that fits snugly inside the other
• safety scissors

Additional Materials:

• nose flutes
• spools of thread
• wire hangers

Sound Fundamentals

Sound is a form of energy. Sound energy is created when an object or objects vibrate. Sound can be classified as noise, speech, or music. Noise is sound with the vibrations are jumbled or irregular. In musical sound, the vibrations are arranged in a pattern so they are organized and regular.

The following activities explore three of the fundamental charactoristics of sound energy:

1. Sound – created by objects vibrating,
2. Loudness – in terms of louder/softer,
3. Pitch – in terms of higher/lower.

Musical Instruments

Musical instruments can be categorized into three groups:

1. percussion,
2. strings,
3. winds.

PERCUSSION INSTRUMENTS

Percussion instruments create sound when they are struck by a hand, mallet(s), or stick(s). Drums are thought by many to have been the first musical instruments, though we don't know for sure. Drums, and the rhythms they create, form the backbone or foundation of many types of music including chant, dance, ceremonial, and popular.

To Do:

1. cut the neck off the balloon,
2. stretch the body of the balloon over the cup,
3. thumb away on your drum!

To Know:

Technically, a hollow log is not a drum. A true drum makes a sound because of a tight vibrating skin that causes the air around it to vibrate. By stretching the skin tighter, you can change the pitch it produces.

Try These:

1. Try hitting your drum harder, then softer. Does the sound get louder and softer? Does the pitch go higher or lower?

2. Try a different sized cup, larger or smaller, it doesn't matter. What happens now?

3. What is the relationship between the size of your drums their pitch?

4. What is the relationship between how hard you hit your drum its loudness?

STRING INSTRUMENTS

String instruments include guitars, violins, pianos, violas, cellos, and bass, though there are many different kinds throughout the world. When a string is plucked, tapped, or bowed, it vibrates and produces a sound.

To Do:

1. make a hole in the bottom of the cup,
2. cut a rubber band and knot one end,
3. thread the rubber band through the hole with the knot inside the cup,
4. hold the cup to your ear, holding the rubber band straight out with your other hand,
5. now pluck the rubber band with your thumb.

To Know:

The tighter the string, the faster it vibrates and the higher the pitch. With the same amount of tension, a longer string will have a lower pitch than a shorter string. The pitch of a stringed instrument depends on three things:

1. the length of the string (shorter or longer = higher or lower pitch),
2. its weight (lighter or heavier = higher or lower pitch),
3. how tightly it is strung (lesser or greater tension = lower or higher pitch).

Try These:

1. Try pulling the rubberband tighter, then less tight while plucking it. Does the pitch go higher or lower?

2. Try the previous with a different sized rubberband, either larger or smaller. What changes this time?

3. What is the relationship between the size (length and wieght) and tension of the rubberband to its pitch?

WIND INSTRUMENTS

Wind instruments are usually divided into three groups:

1. flutes,
2. reeds,
3. horns.

A flute makes a soft hollow tone when air is blown across a hole, causing the air in the tube to vibrate. Reed instruments have a flexible reed or reeds that vibrate. Horns get their sounds from the vibrations of the players' lips.

Tooters

To Do:

1. take a straw and flatten one end with your teeth,
2. cut the flat end to form a "V" (reed),
3. place the reed in your mouth and vibrate your lips,
4. now insert the reed straw into the larger straw,
5. experiment with your tooters by blowing air through them. Try to make both lips vibrate when you blow.

To Know:

Blowing through the reed sets up a column of vibrating air in the straw. You can change the pitch by shortening the length of the straw. The shorter the straw, the faster the vibrations and the higher the pitch.

Try These:

1. Try blowing harder, then softer. Does the pitch go higher or lower? What changes?

2. Try blowing while making the straws longer or shorter. What happens now?

3. What is the relationship between the length of your straws and the pitch? When is it higher or lower in pitch?

ADDITIONAL ACTIVITIES

Nose Flute

The nose flute works the same way as blowing across the mouth of a bottle.

To Do:

1. hold the flute up to your mouth as shown,
2. with your mouth open, take a deep breath and exhale through your nose,
3. now try it with your mouth closed. What happens?

To Know:

By exhaling through your nose, you're blowing air across the opening over your mouth, this makes the air in your mouth vibrate, producing sound.

Try These:

1. Try blowing harder, then softer through your nose (this doesn't work well for kids with colds :-) Does the pitch go higher or lower? What changes?

2. Try blowing harder, then softer while opening and closing your mouth. What happens now?

3. What is the relationship between the size of your open mouth and the pitch?

Stereo Musical Hanger

To Do:

1. tie both ends of a piece of thread (about 3 feet long) around each end of a bent hanger,
2. wind a few inches of thread around both of your index fingers,
3. place the fingers in your ears,
4. tap the hanger against a hard surface.

To Know:

When you strike the hanger, it vibrates. The vibrations are transmitted to the string, the fingers, and into the ears.

Stereophonic sound is sound heard from two different locations by two ears. Stereo hearing occurs when sound arrives at each ear with a different loudness, and at slightly different times. The brain then interprets these subtle differences.

Try These:

1. Remove one finger from your ear when you stike the hanger. Do you lose the stereo sound?

2. Have someone hold the thread after you strike the hanger. What happens?

3. Change the shape of the hanger. What happens this time?