I have a rather loud/booming
voice which has sometimes caused me embarrassment over the years. I've realized that I need to moderate it to the level where I feel like people aren't going to hear me properly (like in a louder setting), but they can almost always hear me just fine.
But that's just to do with the type of voice I have, though I tend to get louder when I'm excited...
I can be "loud" though, as in boisterous and talkative, when I feel comfortable and I'm enjoying myself. If I go to a rock concert I certainly do a lot of screaming and singing along
My brother is similar - he's a probably ISTJ. We both have loud booming voices
and I don't see him that often these days (different continents) but when I do I'm always like "man, this guy can be LOUD." But he's definitely an IxxJ, I have no doubt about that. No way is he an extrovert.
Normally...well, it depends. I'm definitely not a dead silent introvert. It depends on my mood, what kind of company I'm in. Sometimes I can get quite dominant in a conversation, sometimes I sit back and listen to others and don't say much - usually I'm somewhere in the middle.