This item has been languishing in my bookmarks since January: Many children 'hear voices'; most aren't bothered.
The gist is that 15-ish percent of kids hear imaginary voices, and that the majority of the time, the voices don't interfere with their thinking or cause them much distress*. The voices aren't linked to schizophrenia, violent behavior, or any real ill effects. It's part of their lives. Part of how they think.
What struck me at the time is how much of my own thinking could be framed as "hearing voices." Don't worry, the neighbor's dog isn't telling me to kill, aliens aren't informing me of imminent planetary destruction. But I often think in a babble of voices: friends, family, voices from books and movies. Often it's a dialogue between me and the other voice. When I'm writing I hear character's voices talking. Sometimes I talk to a younger version of myself (usually asking him "what the f@ck were you thinking?"). And while I can't speak for the inside of anyone's brain but my own, I'd wager most other people are the same way. Linear, orderly, point A to point B thinking occurs in bad novels and Psych 101 classrooms. Which is why I don't like most interior monologues in fiction. Easy. False.
The unpredictable, wandering minds of real people, engaged in real life, is more subtle, more fractured, and much messier.
I like messy. I trust messy.
* an interesting footnote: "Although urban children were less likely to hear voices, they were more troubled by them."