Why are those noises coming from the dead shell?
Why are those noises coming from the dead shell?
I assume you're talking about "hearing the ocean" when you put your ear up to a snail shell.
You're hearing echoes of air moving around. I think you also hear the blood flowing in your ear.
According to how stuff works, it is the ambient noise from around you resonating inside the shell. Interestingly enough in a quiet soundproof room you won't hear anything out of a shell. And if you just cup your hand around your ear, you get the same sounds, no sea shell required! Oh, and they say it cannot be the blood from ear because then when you exercise it would get louder, and it does not - and I suppose then the soundproof room trick would not work either.
Here is the howstuffworks page I got this info from, and I just tried the using my own hand without a seashell, and yes indeed I could hear the ocean. :)
HowStuffWorks "Why can you hear the ocean when holding a seashell to your ear?"