We seem to be talking about two different "inner voices." First, the way our actual speaking voices sound to us, and second, the inner voice we "hear" when we think -- the one that never makes it to the outside world.
As to the first, I was astonished, way back in the dawn of time when I first heard a recording of my voice, at how low it actually was. It didn't sound that way to me at all. Now, not quite a year on T, my voice has changed a lot -- it's much deeper and more resonant, and friends who haven't seen/heard me in a while say "Wow!". It sounds
really different to me, but a big part of that isn't the pitch as such, but the feeling of it resonating in my chest (very cool!). One of these days I'll have to make a recording and find out what it actually sounds like.
The "voice" I hear internally, when I'm having coherent thoughts, hasn't changed at all, and I wish it would. I have no idea whether it will change over time, but it seems as if it should.
I wonder how this relates to other ways we experience ourselves which can be quite different from reality: for instance the way our body images can vary from how we actually look: some people with anorexia experience themselves as fat, no matter how thin they actually are. When I go bald, will I still experience myself as having hair?