While treatment of female-to-male transsexuals with androgensdoes lower the pitch in voice, estrogen does not raise the voice pitch in the male-to-female transsexual.
A few years, probably more. Unless you have a feminine voice already, it'll be very difficult to train yourself to speak like a woman. You can't do it through hormones so you'll need to get a voice trainer, and possibly some surgery on your vocal cords. Both are likely to be very expensive.
You have to remember, this is a voice acting role. If you somehow attain a feminine voice, you'll have to train it further for a full, natural range, and depth of emotion. Women speak quite differently than men, so it will take some doing to break your old habits.
Anyway... if I get a new motherboard in time, I'd love to volunteer.
