Seems like I hear it all the time when I am in my docking bay, it is very noticeable. I have 7.1 speakers and they are all around my position. Its actually pretty weird. I wasnt kidding about looking around. If you been sitting here half asleep and you hear it, its a bit freaky.
And the "groaning old men" during hyperspace - there was a suggestion a while back that it was the groans of people reading/posting in the forums, but I hardly ever see negative posts on here - ahem