ok, i was wondering is someone knew how to fix this problem?

Basically, i can hear everything, and it gets really annoying, like, if i were in the Arena Underworks, i could hear a mudcrab squeak nearby.

And when i was in a cave, freeing the slaves, when i was swimming underwater, i could hear a man screaming, and when i emerge, it stops. But when i re-submerge, he starts screaming again..

Does anyone know how to fix this?

Did it start after installing a particular mod? It's really hard to trouble-shoot this without some info. Mods seem most likely to do it, one option is to disable all mods, then enable them one at a time until you find what's causing it.

Also, what mods do you have installed?

What are your entries for the (Water) section of Morrowind.INI?