When I was growing up, I was always too quiet. I was yelled at for mumbling all the time, but I thought I was speaking at a clear volume.
When I got into high school, I took a drama class on a whim. I really liked the class, although many elements of it were difficult for me. One thing I learned from it was how to project my voice. Which I then did all the time. As far as I remember, no one complained about this until I lived with roommates when I was 18, and one asked me to stop yelling all the time. I did not think I was yelling, but apparently I was. So I went back to speaking too quietly for years afterward. These days, I occasionally get a complaint from my niece that I am speaking too loudly, although I do not think I am that loud and others do not agree with her. Still, it's a bit on my mind.
I should probably ask someone who is more likely to be objective about it.