My internal monologue is very much present for me (as I am typing this out I hear it being voiced in my head) but it’s strange; it’s not in my voice, or in any voice in particular. They are just words that my brain processes as being “heard”.
Another interesting thing I took note of, is that most of my physical action is not dictated by my internal monologue. If I’m thirsty and there’s my bottle of water next to me, I will, without thinking that I should do so, grab the bottle and take a drink. If the bottle was nowhere to be seen, though, I would “hear” the words, “Where did I put my bottle?” in my head.
I have that internal narrative all day. Ok so it may not be non stop but for example as I type this out I can "hear" my voice in my head saying it. Lol