Does two cups and a string work?

Yes, two cups connected by a string can work as a basic communication device, often referred to as a "tin can telephone." When one person speaks into their cup, sound waves travel through the string, causing vibrations that the other person can hear in their cup. However, this method is effective only if the string is taut and does not touch any other surfaces, as that would dampen the sound. It's a fun demonstration of sound transmission through solid materials!