I honestly don’t know, but from my mom’s experience in being a bible study group at our church, they were saying how “Out loud” is the best way and were basically making people do “Out loud” prayers, which my mom isn’t comfortable with, so she actually left that group because of how seriously they were taking “Out loud prayers”.
I can ask her later for clarification, since I’m going off memory, but I think if you have someone leave a bible study group because of the “stressing how important out loud is”, I don’t think that is right.