Does The Old Two Cans on a String Thing Actually Work?

It does indeed. The old children’s favourite may have been supplanted somewhat by the relentless march of technology, especially now that almost every kid has a mobile phone and/or access to the Internet, but there is still a lot of fun to be had there.



For those reading this that don’t know, the two cans on a string game involves taking two empty (and preferably washed out) tin cans, the kind you might buy baked beans in, punching a small hole in the bottom of both cans and then threading a length of string in between each hole, tying it in a knot big enough to secure it in the can. Then, when the string is pulled tight, it is possible for one person to speak into the can and another to listen and reply. It also works with polystyrene cups, albeit to a slightly lesser extent. You’d be amazed also at the distance your voice can actually travel using this method.

It is not advisable to use stretchable string for the cans as it just makes life more difficult!

The science behind this game is actually very simple. The vibrations of your voice shake the bottom of the can and that, in turn, vibrates the string. Provided the string is pulled taut and isn’t touching anything, there should be no reason at all for your voice not to travel along the string to be received by your companion at the other end.

In fact, this game actually qualifies as a sort of rudimentary telephone; the theory behind it is very similar.

If you happen to be a parent, this game can keep the kids entertained on rainy afternoons, as well as providing a useful scientific lesson for them. I have many happy childhood memories of playing this game. However, it is very important to make sure that the cans have no sharp edges around the inner rim, for older kids, a simple ‘safety brief’ will probably do, but younger kids might be safer with a little electrical or duct tape stuck around the top of the can (in each child’s favourite colour, maybe? Just a thought). It shouldn’t affect the sound too much, if at all.

It’s amazing the fun you can have with a couple of old cans and a length of string. Hope that helps.