Children make toy telephones by sticking each end of a long string through a hole in the bottom of a paper cup and knotting it so it will not pull out. When the spring is pulled taut, sound can be transmitted from one cup to the other.
How does this work? Why is the transmitted sound louder than the sound traveling through air for the same distance?
The bottom of the cup passes the sound waves to the string, and so on to the other cup. You can hear surprisingly far using a string telephone if help the right way! If the string is kept tight, the sound waves will travel.
Sound waves are basically vibrations. This works as the vibrations from our mouth is gathered in our paper cup and is transferred through the string to the next paper cup. The person holding this cup in their ear receives the vibrations and hear the sound.
