No, that's called aphantasia, it's orthogonal to not having an inner monologue (the "voice in your head"), and there are in fact people who effectively hallucinate on demand.

Which I suppose explains a lot of phrases that make little sense if they're only taken symbolically. Or why some people like long scenery descriptions in books - they can literally imagine it. Unfortunately, I'm aphantasic, so I can't.

Did you get a CT scan or MRI? Or self-diagnosed?