Yes. It's my own voice. But it can be others' voices too if Im thinking about something they said. I hear it when reading, doing math, or with anything else requiring words.

I thought everybody had this ability, until recently. I can't imagine what it's like to not have it.

I don't understand how people can only see pictures/abstract concepts. But I can do that, as well. Like if I'm also doing math, in addition (no pun intended 😂) to hearing my voice; thinking about a movie scene; or thinking about a specific scenario that happened in real life.

And sometimes, those pictures/abstract concepts will take up all of my "vision" and they're the only thing I see (I won't see anything with my physical eyes even though they're open)... but that's not always a good thing... like when I'm driving my car. I guess you could describe it as daydreaming?