How to Make a String & Cup Phone

Have fun with a homemade telephone.

Leave the electronics behind and take a step back in time. A paper cup telephone may take a few minutes to assemble, but it can provide hours of amusement. Not only will the kids be entertained, they will learn a valuable science lesson about how sound waves travel. Start chatting on your paper cup phone by following a few simple steps.

Things You'll Need

• Paperclips
• Sharpened pencil

Instructions

1. 

   Paper is the best cup material for children.

   Poke a hole in the bottom of two paper cups. A sharpened pencil is your safest choice to make the holes. A nail or needle will work as well.

2. 

   A paperclip will make a good anchor.

   Tie a knot around a paperclip with your string. If no paperclip is available, use tape or simply tie a knot at the end of the string.

3. 

   Test different lengths to see what works best for you.

   Measure the string to your desired length. The string can be as long or as short as you want. Test the string to see what lengths carry sound waves the best.

4. 

   String connects the two cups together.

   Thread the string through the hole of one cup so the paperclip rests on the inside. The other end of the string will go through the hole in the second cup. A paperclip should be attached to the other end of the string as well, once it's inside the cup.

5. 

   The cup phone is similar to the tin can phone.

   Stretch the string tight with a cup in each child's hand. Take turns talking and listening.

Tips & Warnings

• Test different types of cups and string to see which ones carry sound waves the best.

• Do not go around walls with the telephone. If the string touches another object, it will not work correctly.

References

• PBS Kids: String Telephone

Resources

• DSO Kids: Tin Can Telephone