conch shells are the best for “hearing the ocean”
@Allie nope, not true. If it was the blood flow, after a hard work out the noise would be much louder, but thats not the case.
The reason you hear the noise is because the shell captures the ambient noise around you and it bounces around the inside of the shell throws it back at your ear. That is why no two shells will ever sound the same because they all have different grooves and bumps. Really though the shell isnt even necessary to show this works. You can just cup your hands and put them next to your ear and you will hear the ocean. Now vary the distance and angle your hands are at and the sound will change.Also if you are in a loud room the sound will be much louder. But if you were in a sound proof room, you wouldn’t hear anything even in the shell.