[ben_w]

Not necessarily.

I have an inner monologue that's my own actual voice*. But I also have a part of my mind which can generate complete ideas.

I know these are two separate things, because at one point I started to notice that I already had a complete idea before the words expressing the idea had been voiced by the inner voice. Indeed, a few times I tried to skip the wasted time/effort of letting the [inner] "voice" do the vocal equivalent of "imagine" those words, only to find that my overall subjective emotional response was annoyance, because apparently that bit of my brain getting annoyed can be felt by the rest of my brain.

* as I perceive it subjectively, not the impression other people get and which I only experience via microphones and playback.