I hear you. When I was a lot less confident, like back in high school, I'd speak a lot more quietly. I've gotten to the point now where I know I'm a loud talker and I'm okay with it. It's not to the point where I'm "yelling" but if people told me to keep it down I'd probably just laugh (unless someone's sleeping or something). Honestly I'd say do whatever makes it easier for you/makes you most comfortable, because that's all that ultimately matters.