At any rate, this post is ironic, since i just got finished writing something about Thomas Edison's poured concrete house idea for people of low income. But anyway, here's my understanding, for what it's worth:
The issue with solid concrete is that it doesnt actually soundproof as well as one might think. Heavy mass is only one principle of soundproofing. Another big one is "de-coupling". When something is coupled it's connected; decoupled = disconnected. A masonry wall can have the same sound transmission class (STC) as a wood framed wall because, though the masonry wall has mass on its side, its very solid and not as decoupled as a wood framed wall which has stud bays that keep the two sides of the wall from touching everywhere; not to mention that the airgaps of the stud bays themselves, if air tight, greatly deminish the noise. Sound travels very well through most any solid object, especially if we are talking about low frequency vibrations like walking, running, moving furnature, etc. You need to add drywall to the ceiling and walls while prividing for as large and air gap between the drywall and concrete as you are willing to subtract from the interior space of the room. The larger the airgap, the more noise you will remove. The reason it is most likely necessary to sheetrock the walls is because the structure seems to be solid, as youve described, and the vibrations can just travel down the walls into the room. We could just use strips of wood (furring) to create the air gap, however this is not the best way to decouple. To Be Continued...
