yo wrote:
I own a raise ranche home that is split into a 2 family house, 1st and
2nd floor.

I recently put hard wood flooring in my living room. The gaps where
the wall and floor meet I used caulk to seal off that bit of space,
thinking it will block some noise. The wall plugs I used electric foam
covers that go inside the plate.

I managed to cut down the noise level I hear from the 1st floor a
little. One of the problems is noise coming from the 1st floor where
the 1st floor door is. There is an almost 1 inch gap under the door.
Is there something I could do to muffle the noise a little without
replacing the door.

I was wondering if anyone also has any other advice on muffling the
noise coming from downstairs.

Before you close off that inch space under the door, make sure it is not
needed for air circulation as in heating and cooling.

Take a look at: http://www.soundproofing.org/

Note: I have no connections with them, but they do have some good
information. The little I have ordered from them was fine.

--
Joseph Meehan

Dia duit