In my one and only recurring nightmare this was the case, I knew I was asleep and unable to burst out of my mind's cruelty. Perhaps it is a way the body remains alive and not perish from the thought that what the mind was experiencing was real, causing possibly a heart attack. I was comatose, aware of the viable world around me but unable to connect and become one with it. Because I was fully aware that I was in a nightmare, I can now grasp what it must feel like to be in a state of a coma, to be a captive in one's body unable to respond to the world around. This feeling can be easily explained with the fact that atonia, the immobility of all muscular ability, is in effect while sleeping.
Atonia is a normal occurrence for everyone during REM or the stage of sleep when dreams occur.
But even though atonia protects the body from physical harm one may cause while in REM sleep, dreams can seriously effect us mentally. Most people can probably remember at least one nightmare they had in their life and the effects it had on their state of being. Even if in a small way, we seem to be somehow forever changed by it. In my nightmare my voice was without sound. His voice was more than capable to assist in my torment.