Conch shell noise

You know how when you put a large sea shell to your ear you can hear a sound like the sea? I never was too sure how that worked. Is it the sound of your own blood pumping away that is magnified by the shell. Or is air caught up in the passages of the shell agitated when the shell is moved. Anyway I've discovered that the local fishermen signal to each other across the bay by blowing into huge sea-shells. And the fishermen use the shells to signal to the villagers that fish are on sale. The shells they use are superb. Absolutely huge. I'd love to be able to buy one. I'd probably never get it home intact so it's probably best that I don't look for one.

I once picked up a small seashell intending if not to take it home, at least to decorate my room with it. On the way back to my room I wanted to buy some matches, and I leant up to the cigarette counter to show what I wanted (I never can tell the difference between the works spirta and spilia, one is a match, the other is a yellow flowered gorse like flower). As I leant against the counter I heard a crunching noise (I hope the shop keeper did not think I had brittle bones) - the shell had smashed. Now the shells the fishermen use, they must be much tougher.