I know that most of what I have to say is off the subject. But there are other factors other than our voice that determine rather we are identified as male or female on the phone.
The problem with medical professionals is that when we talk to them on the phone they will have access to our file on their computer. If our gender is listed as our biological gender, the caller will feel compelled to address us as such. If it matters we can just correct them and say, politely that we are a she and not a he. Myself being a old people pleaser just let it go, because when the person hangs up they are out of my life.
If it bothers you not to be recognized as your gender then correct the person. When it comes to legal documents and doctor's files see if a note can be made upon the file to call you by your real gender and not the one you were born with which is probably checked on your legal files and medical files.
When I applied for my senior citizen transportation pass which allows me to ride free in my county, I was dressed similar to how you see me in my picture. When the lady who was processing my bus pass saw that I was listed as male on my driver's licence, she asked me if I wished to be identified on my bus pass as a male or female. I said female. That's what she did. This identification is just on the computer and not stamped into my bus pass.
Some people will be more accommodating and some will not. We don't know until we are in a position to state our preference. My problems come in in dealing with Social Security and Medicare where I am listed by my biological gender, male, instead of my real gender, female. This problem is self perpetuating when you let it go for over fifty years and all of your job, financial records, and official papers have you listed by your biological gender and not your real gender.
These problems become more difficult to correct if you wait until you near your retirement years. Unless I can be listed as male to female to tie all of my official records together.