his constant professing of what “people” “say” “to him”, especially particularly absurd things that there is no evidence anyone has ever said to him, would also technically meet the definition of him hearing voices - IF he is not lying. Which, to be fair, he could be, because he lies about a lot of shit all the time.
Impossible to rule out. Looks like a duck, quacks like a duck, swims like a duck. I’m no ornithologist but heuristically speaking treating the proverbial duck-like phenomenon as though it is a duck coincides with a statistically high probability of ideal results.