to do it in FCP:
adjust the speed of your audio via Modify > Speed.
then you alter the pitch with the Audio FIlters > AU > Pitch
it;s very un-intuitive, and there are no instructions
and the slider doesn’t tell you what it;s increments are
but another editor & i at least figured out a correlation between speed & pitch:
if we slow audio by 14%, say, (so actual speed is labeled as 86%)
then the pitch goes down,
and we enter a pitch increase in the filter of 280.
that’s 20x the % difference.
we’re always slowing audio, and haven’t tried it the other way, but it probably works?
oh, yeah,
did i mention it sounds crappy?
kind of tinny.
better than what the other poster described
nick