As an Architect who has designed a lot of Condos, of many types, that is townhouses, multi-story apartment like, and so ... the decibel rating of the sound attenuation of the party Walls and the floor Ceiling Assembly is critical.. Background or Ambient sound often masks low level sounds that may be coming through the walls or ceiling... Check with your CONDO Manager to look at the As Built Drawings and see if the Specifications or contracts noted the Actual Sound Attenuation rating of your surrounding walls and ceilings or floors... Usually you can get a sound meter on your Smart phone to actually test how much noise is coming into your unit via the surrounding construction... Check it out... Small things like an Outlet box that leaks sound could leak that telltale TV that is playing music into the night... K