I've always wondered how, exactly, we can hear and comprehend sound and speech in dreams, even though we are not hearing anything when we are sleeping? How does our brain accurtely re-create speech, even with people's unique voices in dreams? In my lucid dreams, I have not really paid much attention to how speech actually sounds, by paying close attention to it. Maybe if we did that, it would sound less real, like when we look at an object in a dream, and just scan it, it looks real, but when we examine it, the object moves, because your brain cannot keep an image steady.