Why Can We Hear a Noise Like Waves in a Seashell?
The pretty idea in this question is just a poet’s fancy and nothing more. The truth is that we only imagine a likeness between the sound of the shell and the sound of the sea. The shell is one of those things which can pick up and make stronger certain kinds of sounds. The wooden part of the fiddle does this. If you take it away and play on the strings without it, they make a feeble, thin, unpleasant tone. The things that make sound resound are called resonators. The body of a fiddle is one, a pulpit’s sounding board is another, and a shell is another.
What the shell picks up are the very slight sounds going on all about us. It is really never quiet and the shell picks up sounds so slight that we do not hear them at all without the shell. Some scientists built a soundproof room. People inside it heard their own hearts beating. But there were cut out of the room all the tiny noises that usually go on, and when a shell was held to the ear nothing at all could be heard. The shell is only a telephone. If no sounds come to it, it is silent and can give nothing out.
