Never assume loud is strong and quiet is weak. If you treat people on the basis on this or others treat you the same then it would not be right.
We don't have to be loud to establish our opinion and raise our demand. There are many ways to do that. But in today's life, it's very common to think we have to be loud. And it's not our fault. Because of the social structure functions that way.
So, what we need to do instead?
Make your point valid and logical. Point out the logic behind what you are asking for, make a list of your reasons. If we can make out point valid then it's not necessary to be loud to establish that.
Show your strength, not necessarily it has to be physical. Our inner strength can also be shown. We don't have to raise our voice loud but we can make it strong. It works.
Make yourself listen and noticed. People will not listen to you even if you choose to be loud. It's necessary to be different, do something positive, bring some positive change so people can easily notice you.
Grow yourself as a person. It's not about your job, designation or power people will take seriously. Rather it's you. So it's very necessary to make ourselves grow as a person; powerful, knowledgeable, respectable.
Ware the 'quite' mask if necessary. Never feel awkward if you are introvert. It does not actually matter if you fulfill all the other criteria which require to make yourself strong. So, rather thinking about coming out as an extrovert and making yourself loud; think about making yourself strong. Our inner strength can conquer anything.