How to Make a Telephone with Cans

Why not make your own phone? Here’s a great way to learn how sound travels and to have fun at the same time.

You’ll need 2 empty can (like a can of baked beans), string and a hammer.

How To:

1. Wash the empty cans – unless you want to get beans in your ears!
   The end that has been opened will be the phone’s receiver, and the other end will hold the phone’s wire.
2. Hammer a nail through the base of the cans to make a hole in the end of each can
   
3. Insert one end of the string through one of the nail holes. Tie a knot in the string on the inside of the can, so that the string stays attached to the can. Repeat with the other can and the other end of string. The tin cans should now be connected to each other.
4. Hold one tin can, and give the other tin can to someone else. Walk away from each other until the string between the can is taut.
5. Speak into the open end of one can while your partner listens to the open end of his can. Switch it around and listen.
6. Now you’ve made your own tin can phones – you’ll be surprised at how much fun you’ll have!

How does it work?

The person at the other end of the telephone hears your message a couple of milliseconds after you’ve said it – after her ears have collected the sound vibrations and sent them to the brain to be processed.