Bob, welcome. Some of our members have been personally involved in constructing their rooms with soundproofing in mind and/or treating room modes, so hopefully they'll be able to comment if they're not getting an early start on that turkey. I'll comment a bit on STC theory. A typical room at home has a background noise level on the order of 40dB. So, an STC of say 65 would prevent a sound at a 105dB level in an adjoining area from being actually heard in that room. Listening at about an 80dB average level is considered to be "comfortably loud" and no one who values their ears will listen at above a 90dB average. Very brief peaks, especially in material that has a wide dynamic range(i.e. much more likely with classical rather than pop music, and sometimes occurring in movies)might hit about 110dB. So in a kitchen, which tends to have an above average background noise level, there should be no problem with sound transmission if a STC in the mid 60s can be achieved.
