There are some new alternatives to using silicone caulking, however, using
the silicone as described is the cheapest way to soundproof a wall.
Dampening has come a long way recently and new products
have been developed that offer good alternatives to silicone which work
better. These new products have visco-elastic materials (fancy
word for sticky and stretchy), which are used
as layers between two stiff materials, and do wonderful jobs
in stopping noise.
One company offers already sandwiched materials
using a good visco-elastic product. It works well, but is expensive,
because they have to assemble it and then ship heavy stuff across the
A newer and better material exists
is called Green Glue. It allows you to apply the visco-elastic material
yourself (easily and it is actually hard to do wrong). It
is applied like the silicone in the space between the two
sheets of sheetrock. It
costs $0.50 to $1.00 per square foot of wall space, so it is affordable
for most projects. Details
and links available on the Links page.
New wall construction can really give you the freedom to stop noise from
entering. See the diagram for how to build a new wall. Alternating studs
and splitting the 2x6 bottom and top plate can really work well. The
diagram assumes there is sheetrock on both sides (interior wall), but
the same principle works with stucco, siding, brick etc., for the outside.
Use a 2x6 bottom and top plate as shown. Cutting the 2x6 in half stops
the direct transfer through the wood. Notching where it meets the 2x4
wall studs also disconnects the direct transfer. Insulate per diagram
or later discussions here. This will create a nice soundproofing barrier
that will stop the noise.