In this game, the students must pass on the message through a human telephone line.
A telephone is one of the simplest devices you have in your house. In fact, the telephone connection to your house has not changed in nearly a century. If you had an antique phone from the 1920s, you could connect it to the wall jack in your house and it would work fine.
There are two essential parts to a telephone: the microphone (which you talk into) and the speaker (which you put by your ear).
Inside the microphone is a thin piece of metal called a diaphragm. It vibrates when the vibrations from your voice hit it. As the diaphragm vibrates, it wiggles a magnet to make current flow down the wire.
At the other end is a speaker. A speaker has a permanent magnet and an electromagnet inside it. When electric current pulses flow through the electromagnet, it moves back and forth, attracted and repelled by the permanent magnet. This makes a membrane vibrate, which creates sound. Interference is caused by the tiny imperfections in the wires carrying the electrical pulses.
In other words, the telephone system converts acoustic energy (sound) into electric energy. The electric energy travels along the phone wires and is converted back into acoustic energy at the receiving end.