Help with noise reduction

[Byron Bohlsen]

Hi Folks,

We bought a duplex and are trying the whole house hacking thing. Enjoying the financial benefits but a design flaw I overlooked when deciding to buy is that the steps going down to the basement is shared. While this in of itself isn't a big bother the real problem is the noise spill over between the units. Each unit has a basic interior door connecting to the stairs and we hear everything from the tenant going up and down the steps to him cooking even his laundry machine sometimes. He is a respectful and quiet tenant in general and yet Its loud enough to wake our toddler sometimes!

Any ideas on how to reduce the noise? I was thinking replace the interior doors with exterior grade door with weatherstripping and then carpeting the stairs. However I think in practice it would look/feel strange and make the basement feel alot more disconnected. 

Thoughts?