You've got it wrong - we often look for microphones that don't pick up the sound of you touching it, a noiseless mic would be silent and no use - think about what6 you're asking. Sounds from your space leak from where they're created to where in this case, they're not wanted. A mic is designed to capture this noise, NOT reduce it. The only thing that soundproofs space is mass and materials sound passes through that soak up it's energy. You cannot buy anything magical to reduce sound transmission - that's why soundproofing is so expensive. It's also heavy, and a house that is lightweight probably won't take the weight of doing this.
We can advise on many mics that are really sensitive and can collect very feint sounds, but that's not what you want. They could wear earplugs of course, but without structural work to stop sound energy escaping, equipment cannot help.
Have we really understood what you want to do? You cannot find any gizmo on Google/Amazon/Ebay that prevents sound in one space leaking through lightweight walls or ceilings - unless it's plasterboard/brick/concrete/MDF/plywood and air spaces. Nothing that is electrical has been invented yet.