On Tue, 29 Dec 2009 12:15:47 -0500, Sam Takoy
wrote:

Hi,

I have posted a sound insulation question before a received a lot of
useful information.

I would like to revisit it one more time. I'm trying to sound insulate a
second floor bedroom from the kitchen directly below it. The bedroom has
3/4 pine nailed directly to the joists.

So I'd like to ask a very specific question. Is there some kind of soft
material that I can add to the kitchen ceiling joists as strips that
will absorb acoustic energy and therefore act as sound insulation (at
the same time not affect the structural integrity of the ceiling drywall.

Many thanks in advance,

Sam

What kind of sound is being transmitted? Did you try eliminating the
source of the sound? Insulating for sound is very specific and the
most effective barrier will involve more than one step. A small hole
along side a pipe will transmit sound, so caulking or using expanding
foam is your first step. Seal around heating ducts, electrical holes,
etc. Then, (loosely) fill the voids with poly batting or fiberglass
insulation. Sound deadening can cost much less during new
construction or renovation. Where I live they test loud sirens every
first Wednesday of the month for 5 minutes (every dog starts howling
too)--annoying but not much can be done here except ear plugs or
relocation.