Cup Phones

Supplies

• Paper cups (2 per pair)

• String or yarn (approx. 2–3 metres per phone)

• Sharp pencil or skewer (for poking holes)

• Tape (secure string)

• Markers or stickers (for decorating)

Steps

1. Poke a small hole in the bottom of each cup using a pencil or skewer (adult help recommended).

2. Thread one end of the string through the hole in the first cup from the outside in. Tie a knot inside the cup or tape it down so it doesn’t slip through.

3. Repeat with the other end of the string and second cup.

4. Pull the string tight between the two cups so it’s stretched straight.

5. One person talks into one cup while the other holds the second cup to their ear — it really works!

6. Let kids test different string lengths, try whispering, or decorate their phones.

Other Information

• This is a fun way to introduce sound science: sound waves travel through the string!

• Try experimenting with: adding more cups to “conference call.”

• Encourage kids to guess why it works and talk about vibrations and tension.