Vibration, picking up vibration. I real like the comment about discos using. Technics sl 1200s and have hundreds of people on the dance floor and Not worrying about vibration. I guess of if your home is dead silent, you really worried about vibration. YOU must have super hearing....
I do. Also super logic. Like I deduce people jumping up and down screaming and shouting zonked half out of their minds on alcohol and who knows what all else are probably not all that likely to be listening intently, or capable of it even if they wanted- which they don’t.
Pretty sure that is why they call it a club, and not a meeting of the audiophile society.