Well I'll be damned

probably paranoia but i feel theres secrets in the dungeons that havent been discovered. who knows though.

If the mine instances are way up in the sky like the other dungeons, it's also possible they coded it so another mine is phyiscally next to the one you're in up in the sky space.

Because I've heard the same sounds, but only in some of the mines, and it really sounds like a seeker is just on the other side of a certain wall, with no apparent way to get there.

its the same with the black forest crypts where one can hear a troll sometimes
so i believe that those cells are next to each other like coolAlias wrote

It's very well likely these are just ambient sounds, just like we have in the crypts in the Black Forest and the Swamp and the Frost Caves in the mountains.

Thorin :)