- Some people describe hearing their internal monologue, which I take to mean something like: they have an internal monologue, and it manifests as a voice that only they hear. These people are analogous to those who see things they picture in their mind's eye.
- Some people describe not hearing their internal monologue, which I take to mean something like: they interpret "internal monologue" as a metaphor for their train of thought or stream of consciousness; they think of themselves as having an internal monologue (i.e., they are thinking in language), but don't experience it as a voice. These people are analogous to all of the aphantasics surprised that the mind's eye isn't just a metaphor.
- Some people describe not having an internal monologue. I suspect these people are a mix of those who think in language but interpret the term "internal monologue" as requiring hearing a voice, and people who'd describe their thought process as nonlingual in some way (visual, abstract, etc.)
Across these characterizations, different people describe their thought process(es) all over the place WRT to how compulsory/voluntary/consistent they are. Some of the people who "see" things do this consciously; others can't help but picture things they read or think or hear. Some people describe a conscious/conditional train of thought, while others describe one that is racing/intrusive/incessant.