in Dunbarrow Cove (you have to get it for some M$ pionts) there is a pirate ship called The Black Flag

if you go into the ship and in the second level there is a guy named Jak Silver

in that room you can here what sounds like the sound that is made whan you drop a Sigil Stone but I cant find one anywhere

has snyone else noticed this

maybe you been hittin the skooma to hard?
I think you just bumped into something.

he he he I started a new game to see if it was that and still I here it only in that one room on the middle of the ship