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Indoor activity

Paper Cup String Telephone

Build a classic string telephone and discover how sound travels through solid objects to talk to your friends from another room!

Ages 3-12 0-1 hours Education 8/10

Materials

  • Paper Cups
  • Push Pin
  • Scissors
  • String

Illustrated Steps

1

Poke the Holes

Have an adult use a push pin to make a small hole in the centre of the bottom of each cup.

2

Thread the String

Thread a long piece of string through the holes in both cups, going from the outside to the inside.

3

Knot and Secure

Tie a large knot at each end of the string inside the cups so it doesn't pull through.

4

Test the Line

Pull the string tight between two people. Speak into one cup while the other person listens!

What You’ll Create

Ever wondered how sound travels? 🗣️ Build a Paper Cup String Telephone and find out! By connecting two Paper Cups with a long piece of String, you can send your voice across a room. The string vibrates as you speak, carrying your secret messages like magic to your friend’s ear.

Have fun!

  • 🤫 Try whispering as quietly as you can and see if your friend can still hear you.
  • 🚪 Go around a corner or into another room to see if the telephone still works (just don’t let the string touch the wall!).
  • 🎻 Gently pluck the tight string like a guitar string and listen to the ’twang’ through the cup.
  • 👫 Add a third cup in the middle of the string to see if you can have a three-way conversation!

Why It’s Amazing

  • Acoustics Basics: Teaches children how sound is actually a series of vibrations that can travel through solids like string. 🔊
  • Communication Skills: Encourages clear speaking and active listening between partners. 🗣️
  • Scientific Method: Invites kids to experiment with string tension and length to see what works best. 🧪
  • Collaborative Play: A perfect activity for siblings or friends to do together. 🤝

Pro Tips

For ages 3-5: Keep the string shorter (2-3 metres) so they can still see each other easily. Emphasise that the string must be ‘straight and tight’ like a bridge.

For ages 5-8: Experiment with different types of string (wool, fishing line, cotton thread) to see which one carries sound the best.

For ages 8-12: Challenge them to explain why the sound stops if you grab the middle of the string while someone is talking!