Why can we 'hear the ocean' in some shells?

I'm pretty sure it's not really the ocean making that noise, so what is it?

Why can we 'hear the ocean' in some shells?
Actually the sound effect we feel from shells are in no way created by ocean,what we are listening is the sound of a area which is hollow and closed from surroundings but it resembles like ocean waves so it is believed that ocean is showing its presence in shell.
Reply:the sound of the ocean is from the movement of the wind caused by waves.



Seashells are made in waves so the sound of air in the shells sounds like the sound of the air caused by the waves.



like an accent.
Reply:It is true. The you can listen into a seashell is very similar to the sound of waves in a windy day. But it's merely a coincidence because the shell doesn't actually "store" that sound inside. It's just a physical effect produced by sound waves when circulating through the shell. The effects happens because of the shell's form (snail-spiral). It's a kind of an echo that the shell captures from the outside world and whispers it to the listener's ear... Let's keep that magic!
Reply:itis called echo