What to do:
- Punch a small hole in the bottom of two paper cups.
- Attach a string from one hole to the hole in the other cup. Tie knots at both ends to hold the string in place.
- Allow children to carefully pull the string tight, and to talk to each other using the cups. The string carries the sound from one to the other.
- Try with different types of string or with a string loose instead of tight. Compare the results.