I started working on the feminization of my voice. My speech therapist gave me this video so I can learn more on the topic (sorry it's in French, couldn't find something similar in English).
This video is made by another speech specialist fro Liège, Belgium, who's been studying the topic for some years now. She explains the different surgery techniques, the therapies and their results.
She explains that there is currently no research on the difference between male and female voice, and more importantly, between male and female speech patterns. Everything we know is based on anecdotal evidence. Like for example, the fact that women tend to have more variation in the tone in their sentences, or the fact that men tend to end sentences with a lower tone, rather than a higher one in women. Of course, speech patterns may vary from one langage to another, which could (partially) explain this situation. But this is the data they base their work on, by default.
But the underlying question is this : assuming they are indeed common and well spread in the general population, where do these speech patterns come from ? Are they only cultural ? Kids learning to speak like people around them of the same gender ? Is it biological (besides the natural height which is, obviously) ?
Has anyone here heard of any significant study on the subject ?