most tuners have a function to change the reference pitch, like peterson, TT's and i imagine pitchblacks etc.
You won't be able to decide for yourself though. the idea has already been planted (a bit like Inception), the only real way you could decide something like that is if someone played 2 pieces of music to you blind folded and said which do you prefer. there would also be a control group etc etc. IF you or a group consistently picked the 432 as the ref freq that made you feel better about the universe (this is assuming the question was something along the lines of "which of these makes you feel better about the universe") but not knowing which piece of music was 432 or 440, and preferably both groups wouldn't really know much about music, then this whole thing might hold some water.
If you knew in advance that it was an experiment designed to prove that 432 is a fundamental frequency in tune with the universe, then it defeats the purpose of the experiment, because it's instantly going to lead to subjective interpretation based on the sunbjects propensity toward skeptical or wooly thinking.
and you basically already know why you're trying it out, so whatever your opinion is, for or against, is biased in advance.
phew.. experimental psychology considerations are a b***h
