That's fascinating! I've lived in apartments or condos most of my life and it just wasn't an issue. Possibly structural, possibly cultural - people tended to live a quiet life, unless you were unfortunate and got a real party neighbour. I live in a house right now and in some ways my life is louder (closer to the loud streets, neighbour's barking dogs and lawnmower and snowblower machines and constant little constructions etc).