See Sound Waves

We know we can hear sound made by musical instruments, radios, car horns and voices, but did you know there is also a way we can “see” sound? Sound is a vibration, or wave, that travels through the air. Sound waves are invisible to our eyes; unless we find a way to make the sound waves move something that we can see. In this activity, your child will use different noise-making objects to cause sound waves and make sand visibly move.

Materials

• Cereal bowl or small mixing bowl
• Plastic kitchen wrap (commonly known as Saran Wrap or Cling Wrap)
• 1/4 teaspoon of sand (alternatives: sugar or salt)
• Noisemaking items: options include using your voice to hum, banging a metal spoon on a metal baking pan, a noisemaker/party blower or a musical instrument

Directions

1. Wrap a bowl with the plastic kitchen wrap. Be sure to create a tight cover across the top of the bowl as if you were creating a drum.
2. Gently sprinkle about ¼ teaspoon of sand onto the kitchen wrap.
3. Put your mouth near, but not on, the bowl. Make humming noises. Does the sand move?
4. Try making noise with other items such as banging on a metal baking pan with a spoon. Remember to place the object very near to, but not touching the bowl. Does the sand move?
5. Try the experiment with various noise making objects from around your house such as a noise maker/party blower or a musical instrument.

This craft comes to you from the creators of Ready Jet Go!

Iowa PBS STEAM Activities and Crafts provided by PBS KIDS Parents.