Noise is mostly subjective perception. What I find bothersome, you may not and vice versa. Even an attempt at measuring SPL with a meter when driving will include contributions from tire, wind, engine, etc. so narrowing the source down to just the tires will be tough. IMO, above about 45mph, the main noise contributor is probably wind given the less than aerodynamic shape of the 4R. Rumor had it the glass thickness was actually increased as a running change after the first year or two in an attempt to reduce wind noise.
That said, Tirerack does include owner's noise perception as a review category for tires they carry. However, one has to remember this is a subjective rating and most folks are also comparing their new tires to the worn out set they just replaced. Our auditory memory is very very short in reality (recovered audiophile, here).
I've been running a set of Michelin Defender all seasons for a number of years now...long enough that I should probably check to make sure they haven't aged out at this point...with an 80K tread warranty and the 4R splitting time with the convertible during good weather, I'm not close to wearing them down yet. Anyway, they've been the quietest tire I've tried...previously were factory Bridgestones and then a couple of sets of Continentals (can't remember which model). I do run my pressure around 35-36 psi, tending to prefer a firmer ride (I also upgraded teh 4Runner with stiffer springs/shocks as well as doing the same for my convertible, which already came with a factory sport suspension). Intuitively, I would expect higher pressure to actually make for a somewhat quieter ride (less contact area) while increasing firmness/decreasing comfort somewhat.
Will all of my tires, I've found the actual road surface seems to have the biggest impact on tire noise. Can't remember much about the factory Bridgestones, but the Contis and Michelins noise could be non-existent on some surfaces and then roar like an AT on others.
Good luck!
