Acoustical caulk, if installed as a full load into the open seam or joint will maintain the STC of the wallboard, (sheetrock, drywall, etc), but this entails a lot of caulk.

You need to caulk the full depth of the seam, not just lay a bead in it.  “Backer Square” helps here; it’s a closed cell foam (far superior to open cell foam ‘backer rod’ commonly used by contractors to reduce the amount of caulk needed in seams).

The technique is to apply the Backer Square (1/2″X1/2″ or 3/4″X1″) where the wallboard is to be installed with a bit of a recess to as to leave some room for the caulk.  It has an adhesive backing, so is easy to install and won’t move as the caulk is used over it to fill the gap.  This saves caulk and saves time caulking.  On a big job, it gets tiresome squeezing the handle of the caulk gun!

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