What's funny is, I have complete aphantasia, but I can imagine a ball, I just can't see it. If you ask me what color it is, I would say white, because I imagined a baseball. But I can't see it, I'm just thinking about it.
I wouldn't say "hear", but I do have an inner monologue. When I read, I have an experience of the words in my mind. But similarly, when I look at the world, I have an experience of what I'm looking at, while I'm looking.
The difference comes when I close my eyes vs. block my ears. When I close my eyes, I don't see images, I can't voluntarily make images appear. But with my eyes and ears blocked, I can still think words - my inner monologue - which I experience in much the same way as I do when I'm reading. I can't conjure other sounds though, which is why I don't really consider that equivalent to "hearing" - it's not sound, it's the concept of words. I don't have any analogue of that for images.
Ordinary aphantasia doesn't imply anything about lack of inner monologue. Some people apparently do lack an inner monologue, and if they're also aphantasic, that's been described by some authors as "deep aphantasia". But there's no evidence that the two conditions are related, except in a kind of conceptual sense.
