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Make a homemade Kazoo musical instrument – a science experiment to create vibrations of compressed air (sound)

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Homemade Kazoo

Ah, the sound of beautiful music. But what some will call music, others will call noise. The lab rats and monkeys are partial to Metallica while Geek Slop is more of a Beethoven aficionado. Put the two groups of musical tastes together and well, you have a big fight over what radio station to listen to. In this experiment, we’ll create a musical instrument called a Kazoo. With it, we’ll make beautiful music… or noise, depending upon your musical preference.

1 – Cut a small square of wax paper, about 1 inch larger than the end of your cardboard tube.
2 – Center the wax paper square over the end of the tube and wrap the edges.
3 – Put the rubber band around the wax paper so that it holds it in place.
4 – Place the open end of the tube to your mouth and blow, talk, sing, etc. When Dad’s turn to use the kazoo comes, turn the tube around the other direction before handing it to him and appear to be puzzled that he cannot play such a simple musical instrument.

When you blow into the Kazoo, the wax paper buzzes and vibrates to amplify (make louder) the sound of your voice. The sounds that we hear with our ears are actually “waves” of compressed air. Sound waves occur when air is compressed and then suddenly stopped creating waves of air that vibrate our ear drums to make the signal our brains interpret as sound. All sound is nothing more than waves of air hitting our eardrums.

The sound of your voice seems to be made louder by the kazoo because the kazoo resonates or vibrates with the sound of your voice. As the air compressed by your voice travels down the tube, the wax paper on the end vibrates. Harmonics, which are the combination of many little sound waves all mixed together so they sound like a single sound, are created by your voice. These harmonics are also amplified by the kazoo although not all of them are amplified by the same amount. These small variations in amplification give the kazoo its distinctive sound.

Interesting sound facts

  1. American composer John Cage (9/5/1912 – 8/12/1992) was a famous composer known for his non-standard use of musical instruments. In 1952, he wrote and performed a very controversial piece known as 4’33” (meaning 4 minutes and 33 seconds). The piece consisted of three movements where he sat at the piano for 4 minutes and 33 seconds and played absolutely nothing at all.
  2. The note, Middle C , with a frequency of 256 Hertz, is near the top of the singing range of a typical adult male voice. It is also near the lower end of the singing range of an adult female voice.
  3. When fiber-optic cables are used in the telephone system to transmit the sound of a person’s voice, a voice on the telephone becomes coded as flashes of laser light. These pulse millions of times per second. Light travels more efficiently in long fiber optic cables than it does as electric signals traveling through copper wire (the traditional phone system construction).
  4. In the deep ocean . the sperm whale uses sound to stun or kill its prey. Its sends out loud grunts, immensely powerful bursts of sound (or waves) that can disable nearby fish, squid and other victims.
  5. In the recording studio any stray sound is a nuisance and affects the qualify to the recording. In sound studios, the walls, ceilings and floors are covered with sound-absorbing substances, such as wavy-surfaced tiles and thick carpets. There is a continuing search for ‘acoustically dead’ materials that absorb all sounds.

Parent/Teacher/Advanced Notes

Here are small snippets of facts about sound that may make it easier for the student to understand:

  1. Sounds are nothing more than tiny shaking movements of the air.
  2. Sounds are made when a material vibrates.
  3. Fast vibrations make a high sound, and slow vibrations make a low sound.
  4. Large vibrations make a loud sound, and small vibrations make a quieter sound.
  5. Sound can travel through materials.
  6. Hard materials can reflect sound so that the sound travels back in the opposite direction. This is called an echo.
  7. Sound moves through the air at 340m per second.

Experiment Supplies

Supplies: Cardboard tube, Wax paper

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