Quiet is almost completely dependent on your neighbors ability to act like they are in a communal situation. To help with this I would request top floor.
I agree with what everyone has said. We were in the 70's last March, building 10 on the top floor. It was extremely quiet and we never heard any of our neighbors. Fast forward to last October when we stayed again. This time in the 90's and still on the top floor. Our neighbors next to us were atrocious. No consideration for anyone around them.
Dh and I use videos on Youtube of box fan noise. It's free and easy to use. Sometimes we use headphones, but lately we've just been playing it at full volume on Dh's phone.
i was ground floor in the 50s building and i didn't hear anything! i was also there at a time with lots of cheerleaders and softball players. but like others said, it's gonna depend on who your neighbors are.