Street Noise in BR. Will flooring attic above BR help?? Any sound consultants in CT?

Sound is transmitted in two primary ways. Through openings such as small cracks and directly through materials. What stops it is to close up the cracks and add m to reduce transmission through materials. The first place I would look is to windows. Caulk and glaze them where needed. Add storm windows if you don't have them. Caulk the inside of the windows too, not just the outside. Caulking the top and bottom of the baseboard may help. Putting some sort of sound absorbing material i.e. foam in a shroud around vent intakes and outlets may help, may not. Adding a floor to the attic may help a little, I would use drywall as it is dense, cheap and fire resistant. Do what is called fire taping it, by putting just the first coat of mud and tape. It would not make a floor that can be walked on though.