My apartment is fairly soundproof as I rarely hear any noise from my neighbors (or perhaps I don't have many neighbors). I usually have the music on to "hopefully" muffle the sounds of paddling, etc., etc. I don't blast the music as that's not allowed, but it may be enough where the neighbors don't hear anything.
On the other hand, if they hear us, it may be embarrassing but Sir and I are certainly beyond the age of consent.
Enjoy!!!