I hear the books in my head most of the time. If I skim or read really fast, then I can't. Sometimes, when I know the author's voice (especially for student papers and the work of friends and colleagues), I can hear it in their voice.

I honestly don't know how I process the info when I'm not hearing that voice. It's different—in part because it's just info, without much regard for tone, style, beauty, or anything like that. If I skim, though, I just want the info. So I don't read literature that way.

I also constantly narrate things in my head. I think those things go together. this Psychology Today article says only 30–50% have an inner monologue, while only 10% report they never have an inner voice. IFL Science reports 82.5% of readers hear the words they read.