I am asking about constructing a non-electric telephone made of two thin plastic cups (these seem to resonate the best) and wire between them to exchange secret messages with my neighbor across the fence.

I've looked into cotton but I've found negligible scientific evidence that this is the most effective engineering solution.

The wire will be fully free floating but support can be arranged along its route.

  • 1
    Science fair aka homework?
    – Mobius
    Commented Apr 3, 2017 at 11:53
  • Supporting the wire will dampen or interrupt the sounds, a "tin can phone" must have the "wire" floating in free air, so the less it weighs the better.
    – Tyson
    Commented Apr 3, 2017 at 12:58
  • Genuine DIY question about a common appliance. I haven't had any homework due for 8 years now (I am 31). I've also done my research and couldn't google anything. Cotton wire sounds like a bad solution and there's no support to indicate it is even "above average" from all available strings and wires. Commented Apr 3, 2017 at 13:01
  • Google "tin can phone" there are many search results, including: en.m.wikipedia.org/wiki/Tin_can_telephone
    – Tyson
    Commented Apr 3, 2017 at 13:42
  • @Tyson, thanks. I did but it did not provide any information about the qualities of the wire. Commented Apr 3, 2017 at 14:08

1 Answer 1


You want very stiff taut wire. Otherwise you will have to pull it VERY tight to pull it to the limits of its springiness so the sound won't get dampened by that spring action.

Also preferably nonconductive. Maybe something in the FRP/carbon fiber family.

My vote is for fiberglass electrician's pulling tape. Nonconductive, stiff and mad tensile strength.

  • I'm afraid I can't vote this up but I will purchase some of this wire and perform benchmarking using a sound level monitor Commented Apr 3, 2017 at 14:50

Not the answer you're looking for? Browse other questions tagged or ask your own question.