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Science Rocks!

String Telephone


your results

Sent in by:
Betsy of Bronx NY

Rrrring, rrrring, rrrring. It's a telephone made from string.

Materials Needed

  • two plastic cups
  • some string
  • paper clips
  • sharpened pencil for poking holes



  1. With the pencil, carefully poke a small hole in the bottom of each plastic cup.
  2. Tie the paper clip to one end of the string.
  3. Thread the other end of the string through the hole in the bottom of one of the cups. Be sure to thread it from the inside of the cup. The paperclip will keep the string from going all the way through the hole.
  4. Then thread the string through the hole in the second cup, but this time do it from the outside of the cup.
  5. Tie the second paper clip to the other end of the string. The paper clip should be inside the cup, just like the first paper clip.
  6. Then, pull the cups so that the string is tight and have one person talk into the cup while the other person holds the cup to their ear.

Now it is time for you to experiment. Think of a question you want answered. Like, what is the farthest distance you can get the telephone to work using string? Would the sound go farther if you used empty soup cans instead of plastic cups? What about using two different sized cups? Make a prediction. Then change one thing-that's the variable-and test it out. Be sure to tell us what you thought was going to happen and what actually did happen. When you're done, send your reports to our special feedback area. Every week we'll post new results from ZOOMers' string telephone experiments.

Some of your Results

Paul, age 5 of Turner Valley, AB wrote:
It kind of sounded very weird at first, but then it actually sounded OK after. I figured the string had to be really tight!

ZOOM Fan wrote:
It kind worked when the string was tight but it was so close you could still hear whoever was talking so we couldn't tell if we could hear throuht the cup or not. It sounded very muffled.

Riley, age 13 of Syracuse, NY wrote:
It sounded weird and fuzzy

Meara, age 11 of Trim, IRE wrote:
it was good, and we learnt that if you put a cup to your ear you can do stuuuuf

Emma, age 12 of Trim, IRE wrote:
It works better with a big cup than it does with a small cup.

Elliott & Craig, age 10 of Trim, IRE wrote:
It sounded real funny and it was real fun to make

James, Harry, Charlotte of Trim, IRE wrote:
It was Quite faint at first but after a while we could hear each other it was great fun to learn about sound on the string telephone.

Tara and Sophia, age 9 of Trim, IRE wrote:
It did not work very well because we could not understand what we were saying but after a while it worked. We thought it was brilliant.

Karl, Steven, age 11 of Trim, IRE wrote:
i was having a little trouble with the hole but when I done it I used it with my boy cousin here he is. hi my name is seven I found it really fun to do. I could not get the string in to the cup but I got it in the end I got it was really really really really really fun.

ZOOM Fan wrote:
well it didnt really work but my friend and I picked up somekind of signal it sounded weird

Paige and Liam, age 9 of Oliver, BC wrote:
When the string was drooping, it didn't work. But when the string was tight, we could really hear it loud. It was so cool.

Jennifer, age 13 of Sligo, Ireland wrote:
It was realy fun. I couldn't beleive it but it worked. I did it for my science progect...

Kyra & Harley of Waterville, WA wrote:
The first try we used yarn and it didn't work. So now were going to use string. And mabie that will work. then we tride the string it worked but we made the hole in the bottem to big. Then we changed the cup to plastice and it worked. And it worked!!! We notesed that when someone talked into the string would move in circles and viberat. Clearly you can see that you need the right matereles to make this expepement work.

Kalyn, age 10 of San Antonio, TX wrote:
It souned funny

Chasity, age 10 of Simmesport, LA wrote:
The two cups reacted with the string and the sound came out clear on the otherside.

Jenny, age 9 of Cincinnati, OH wrote:
I put it in my brother's room when he had a friend over, they where sounding so clear. That's because they where talking into the cup! It was so cool! I used fishing line.

Kaden, age 9 of Yeppoon wrote:
It was really cool and only works when the tring is tight!

Theresa & Jennifer of Portland, OR wrote:
We couldn't really hear each other untill my older sister told us we really needed to keep the string tight then we could hear each other really well.

Chantel, age 10 of Hyattsville, MD wrote:
With string and soda cans insteed of fruit cans

Josh, age 11 of Evansville, IN wrote:
I was able to hear but not able to under stand

Melena, age 7 of Houston, TX wrote:
It worked like a real telephone!!!

Austin, age 9 of Haverstraw, NY wrote:
It was really clear with 25 ft. of string. I an going to make one with 100 ft. of string.

Kristina, age 10 of Gilbert, AZ wrote:
The string started to vibrate but I couldn't hear what she said.

Kaitlyn, age 11 of Cape Breton, NS wrote:
At first it didnt work but then after I had the string tight it worked.

Philopatier, age 10 of Sydney wrote:
Cotton ranking 4, elastic ranking 1, fishing line ranking 5.

Glen, age 6 of Dallas, TX wrote:
I could here my mom when she talked. At first we forgot to hold the string tight and it didn't work. Then we figured it out and it did work!

Rachel, age 9 of TN wrote:
When I did the string thing I did it with my friend we made it with two soup cans.

Melissa, age 10 of Sydney, CT wrote:
I was testing what will happen if I choose different types of string. Which string will be the most clearest string. I chose the following:elastic, fishing line and cotton and rated them by actually testing them out so far the fishing line was super clear.

Meriam, age 10 wrote:
I tried many kinds of string. I found that the elestichad to be streached to be heard but still it was not clear the best one was the fishing line because you could hear it very clearly and the cotton wasgood as well. Finaly the nylon wool it was a bit blury.

Abanoub, age 11 of Sydney wrote:
The fishing line does work but the sound is a bit blured up. Maybe because it is very thin or maybe because my cups hole was a tiny bit big. The nylon wool is the same as the fishing line but it is abit better. I tried putting it completley on my ear but it was not as good as the sound when the cup was about a centimetre away from my ear. The cotten is very good but the sound is a bit faded. I still think it was the best one.

not yet implemented