Ed, gotta say, thats a short sighted and rather self centric approach. If the SCCA decided to change the sound levels across the board, nearly all classification procedures would need to be looked at or adjusted, and that would impact a ton of people that don't need to be impacted. All cars can't make sound limits without drastically affecting horsepower.
ANY new track had better bend over backwards in the good neighbor department. Nobody wants new noise. The existing tracks often date back to a different time...and things change fast. Heck, parents of 60s kids used to toss 'em in the back of the Vette for a Sunday picnic, and think nothing of it! Fast forward 25 or so years, and if your kid is in the wrong seat of your car and isn't strapped to proper kiddie seat and that to a DOT mandated tether that can take a horizontal pull of 1900 pounds you're in deep doo doo! Times change, and society's tolerance levels do too. Lime Rock has had strict noise limits for a long time and they will only get worse.
Watkins Glen has, believe it or not, noise issues and curfews.
The Hudson, last I checked ran North/South, so I'm not sure what you mean by that "south of or north of" bit.
Any track anywhere near population will have extreme issues in many areas. The search for even a possible site in CT, RI, MASS, NH and VT has taken YEARS and has dozens upon dozens of false starts. I also think that the coasts will be more intolerant of things before those in the middle of the country will be.