Why do you hear the ocean through a shell?

Question

10 points if you know the true answer!!! :O)

Answer 1

The most likely explanation for the wave-like noise is ambient noise from around you. The seashell that you are holding just slightly above your ear captures this noise, which resonates inside the shell. The size and shape of the shell therefore has some effect on the sound you hear. Different shells sound different because different shells accentuate different frequencies. You don't even need the seashell to hear the noise. You can produce the same "ocean" sound using an empty cup or even by cupping your hand over your ear. Go ahead and try it and vary the distance at which you place the cup near your ear. The level of the sound will vary depending on the angle and distance the cup is from your ear.

Noise from outside the shell also can change the intensity of the sound you hear inside the shell. You can look at the shell as a resonating chamber. When sound from outside enters the shell, it bounces around, thus creating an audible noise. So, the louder the environment you are in, the louder the ocean-like sound will be.

Answer 2

You aren't hearing the ocean. You are just covering up your ear and hearing the sounds around you through the shell. You're changing the type of frequencies you can hear by having some of them bounce off something covering your ear. Sometimes it sounds like the ocean.

Answer 3

Impossible for me to get 10 points as professor monkey has already thoroughly answered.

Answer 4

magical - the ocean and all its creatures are trying to contact you.
scientifical - it is the sound of the waves crazhing being reberverated in the hollow curve of the shell.

is that right?