I can tell you about my friend Andrew, the cognitive scientist.
"You hear voices? Ah, I knew that would get your attention. Usually as I'm falling asleep. In fact I know I'm falling asleep when I hear them. And that wakes me up. I didn't want to tell you this and here I am telling you.
What do they say? I don't know. Weird things. But I don't really hear them. I mean, they definitely are voices but at the same time they're soundless. Soundless voices.
Yes. It's as if I hear the meanings of the words that are spoken without the sound. I hear the meanings but I know they are words that are spoken. Usually by different people.
Who are these people? I don't know any of them..."