String Earphones

Materials

• one metal spoon per child
• a long (2-foot) string per child
• a picture of earphones or headphones
• a picture of a stethoscope

Key Science Concepts

• Different objects make different sounds.
• Sounds vary by volume (loud or soft), and pitch (high or low).
• A sound becomes louder when the force of the action that is creating the sound is increased (for example, when you hit a drum harder). A sound becomes softer, or quieter, when the force is decreased.
• Sound is caused by vibration.

Vocabulary

Encourage children to use the terms loud, ringing, and vibrating.

Directions

Ask children if any of them have ever listened to music through earphones: Why do you think people listen through earphones? Then ask them if they’ve ever seen a doctor listening to someone’s heart with a stethoscope. (Show them a picture.) Ask, What do doctors or nurses want to hear when they use a stethoscope? How do you think a stethoscope helps someone hear a heartbeat?

1. Tell children that they are now going to listen through earphones made from a string and a spoon. Help each child tie a piece of string around the spoon. Make a tight double knot in the middle of the string, so that the string on each side of the knot is about the same length.
2. Show children how to wrap each end of the string around each of their index fingers, with the spoon hanging down in the middle. Then have them swing the spoon to make it hit against something, like a table, chair, or bookshelf. Ask,
   • What do you hear? How would you describe the sound?
3. Then have them put their index fingers (with the string wrapped around them) in their ears and tap the spoon against the same object. Ask,
   • What do you hear this time? How would you describe the sound?
   • Can you compare the sound of the spoon when your fingers are in your ears and when they aren’t?
4. Then have children explore tapping the spoon against different objects. Write down descriptions of what they hear.

Reflect and Share

Invite children to share their discoveries. Use any notes you may have taken to help students recall their experiences. Ask children:

• Describe the sounds that you hear through your “earphones.” What do they sound like?
• Does hitting the spoon against different objects make different types of sounds? How would you compare hitting the spoon against wood, plastic, or metal?
• Did any of you notice vibrations with your string earphones? Can you describe what it felt like?