I like to think I have the full range - loud and soft. I often try to listen to people and soon ask them to speäk up or to repeat their words. Nothing like that is ever - or very rarely - asked of me. I use soft voice as well. I bet my yell could be heard a mile away in urban énviŕonment and ten miles in the mountains.
At school, I couldn't speak audibly/articulately, especially in front of a group. When my turn came to read in front of class, people would tell me to speak up. I felt like I was yelling, but they still couldn't hear me. It was stressful, and it only made me more shy. These days, people don't ask me to repeat myself, so I figure they can hear me fine.
Though I'm definitely an introvert, my behavior around those I'm close to is noisy and melodramatic. Yesterday, I mentioned it to my mom to see if my perception of it was right...
Me: "Hey, I was thinking the loudest person in our family—"
Mom: "It's you."
Me: "—is me. Wow, you didn't even have to think about it. "
I'm the one who embarrasses my family by laughing and speaking too loudly in public. When I feel safe with people (and I only feel that way with my family), I have less of a filter. I talk too much and too loudly. Everyone else gets my medium or medium-low volume. Lucky them.
I don't speak loud except when I have to. My estj father is very loud and obnoxious which results in me preferring the other direction.
I use to be shy and quiet, but eventually I learned to grow out of it. Nowadays I'd say I go from medium to medium-low usually, but my voice is deep and monotone often which makes it a bit hard to hear supposedly. Let alone my british accent that occasionally comes out... but it works either way usually. Just not around people like father who had blasted their eardrums with loud noises all their life yelling in thir job. I'm more like the artist, and I only speak up with excited in deep conversations. Basically I have a passionate speech but it very rarely comes out. I can be loud when I have fit in around people but I rarely ever do that because it feels fake.
So my vocal range varies but generally quiet than normal. But not mumbling.
When I am in a bad mood I barely talk at all...and when I do, tis after a long silence and extremely blunt. It is basically medium but a tinge of forcefulness behind it do to irritation.