There is definitely relativity to noise. Once I lived half a block from the interstate, just outside of downtown Chicago. Despite the constant hum, I almost never noticed it, other than the very occasional semi hitting the engine brakes hard, and even that was just kind of a pronounced note out of the background mishmash.
Now I live outside a town of 20,000, in a tiny subdivision, and ten times a day I'm thinking to myself, "What are those crazy neighbors up to?" when they do anything at all, because it's generally so quiet *any* noise is disruptive.
Then again, I've got young kids and a territorial dog now, whereas I was a blithely oblivious 20-something back then. Life circumstances may have something to do with my sensitivity to the noise as well.