wikiHow is a “wiki,” similar to Wikipedia, which means that many of our articles are co-written by multiple authors. To create this article, 76 people, some anonymous, worked to edit and improve it over time.
The wikiHow Video Team also followed the article's instructions and verified that they work.
This article has been viewed 474,377 times.
Do you wish you could have your very own phone? All you have to do is follow these steps to learn how to make your own tin can and string (or cup and string) telephone. This craft also makes for a good science project to learn about how sound travels.
Steps Download Article
1Get a piece of string and two empty cans (preferably soup cans). If you don't have cans or you don't want to work with them, you can also use cups (preferably plastic),such as the ones shown here. Plastic is a little easier to work with than metal. Styrofoam cups do not work well because they are soft and spongy and absorb sound instead of transmitting it. In a pinch, you can use disposable paper cups, but plastic and metal take more wear-and-tear.
2Punch a hole at the bottom of each can just small enough for string to fit through. You might need your parents or teacher to help with this. You can make the hole with a drill, hammer and a nail, or some other sharp, pointed tool. If you are using plastic cups, you can probably just poke a hole with a push pin or any other sharp point. Make the holes only large enough to put the string through and no larger.Advertisement
3Pass the string through the hole and into the bottom of one can or cup. It might help to push the string through with the end of a paper clip or thread it through with a bit of wire.
4Tie a knot in the end of the string that is inside the cup. When you're done, pull the string tight so the knot rests in the bottom of the can. You can tie the string around a little piece of a toothpick if you can't get it to stay with just a knot.
5Place the untied end of the string through the bottom of the other can or cup. Tie a knot, as before, and pull the string tight.
6Get a partner.
7Place the open end of one can over your ear and have your partner speak into the open end of the other can. Make the string as tight as you can. If you've made it correctly, you should hear your friend speak, even if it is a long piece of string. Then, talk while your friend listens.Advertisement
QuestionWhat can I do if I do not hear it?Community AnswerPull the string tighter. Often, we can't hear the sound because the string is too loose.
QuestionWe used a piece of yarn and two tin cans, why isn't it working?Community AnswerYarn has a lot of loose threads that works as a vibration dampener. A taut string will carry the vibration much more cleanly.
QuestionDoes the size of the cup matter?Community AnswerNope, cups of any size should work equally well.
QuestionWhy does my partner hear better if the string is tighter?Community AnswerBecause the noise is from the string vibrating and when it is tight allows it to travel through better.
QuestionShould I use a tin can or paper for my telephone?Community AnswerA foam cup or paper cup will work well. Tin cans have been used to make this for decades, so it works well too.
QuestionHow do I make the string tighter?Community AnswerHave each listener pull on an end, so that it doesn't sag in the middle between the two cups/cans. They must be the right distance between each other.
QuestionDoes wire work instead of string?Community AnswerNo, wire is too thick. If you wanted to use wire, you would have to split it in two.
QuestionCan thread be used instead of a string?Community AnswerYes, a piece of thread should work just as well.
QuestionWhy do foam cups work better than metal cans?Community AnswerThe primary reason is that the foam works as a megaphone for your ears - the sound has increasingly more space to move around before it reaches your ears.
QuestionHow do you poke a hole in the cup?Community AnswerTake a screwdriver or tack and poke a hole into a tin can.
- You can hear your partner better if the string is tighter.
- Using fishing wire instead of string helps sound travel a lot better.
- Can you make "phone calls" around corners? Try it and see.
- Check your sound by speaking and having your friend speak both into and outside of the phone. Does it sound different speaking through the phone?
- Decorate and customize your cups to be more exciting.
- Use a paper clip to make phone line better so that it can vibrate more. And also make sure that the string is straight. If it is not, pull hard but not too hard to snap. If it snaps, tie a knot together to work again.
- Try a three-way call (two strings from one can).
- You can decorate it like a real cell phone, if you want.
- Get 2 tin cans and a piece of string and stick the string on the ends of the tins and it is done!
Things You'll Need
- Piece of string
- 2 clean food (soup) cans (empty) or cups.
- Tool for creating holes