I have several layers of thought going on at any one time. Some are commentaries, some are silly, some are jumping all over the place, if we had telepaths and one got into my head, they'd go insane.
That being said, I'm pretty heavy extrovert... I need to state ideas outwardly; if I don't say an idea out loud, even under my breath, or muttered, it doesn't feel like I've really concluded the thought process. Most of the time I'll be thinking to myself out loud, and even have wild and bizarre conversations out loud with myself, taking on several roles at once.
The same goes on inside my head though, but generally that's when I'm typing or on the computer. I can't type and speak at the same time, there's just some breakdown in the brain that will NOT let me do those two tasks at the same time. One or the other, never both. I can be multitasking a thousand things at once with no problem, but as soon as I hit trying to type and talk at the same time, they both just grind to a halt.
So yeah, my inner monologue only really shows up when I'm busy; when I'm not, it's vocal and aloud, regardless of whether people are nearby or not.
It doesn't matter if they're right. If they can't proove they're right, then they're wrong. No matter how right they may be.