I'm living in a basement apartment, but for some reason the original designer left about a foot airgap between the wall and the stairs up to the second level, so I can hear everything that happens in the house as if it's in my bedroom.
Here are some pictures:
https://www.amazon.com/photos/share/LgzSFJBMLFxP0vqmN9EeVNCb0ie98HQb03duBaAsoarSolidworks mockup:
https://i.imgur.com/NeZpg00.png
I'm thinking of making something with a wood veneer and some rigid foam insulation to help dampen the noise. Is there a more obvious solution I'm not thinking of?
Thanks.