When you are sleeping are you unconscious or subconscious?
"The subconscious mind works best when we are apparently not alert; for instance, while sleeping."
When you are sleeping you are in a subconscious state, but the level at which people sleep varies widely from person to person, and occasion to occasion.
When you are asleep you leave your conscious state and move into a subconscious state as evidenced by your inability to participate in an intelligent conversation. Some people can respond to inquiries during sleep, but the conversation is nonsensical.
Other sleepers will not respond at all to noises or conversation because they are in a deep sleep closer to the unconscious level, or they have been conditioned not to respond even if the conversation is perceived.
Then there are sleepers who are almost still conscious when they sleep, and are able to respond almost instantly to any sound or conversation they hear.
Combine these traits with the variety of sleep levels depending on occasion - night sleep vs daytime nap, bed sleep vs in the car nap, overnight vs in front of TV nap - and the level of sleep is continuously changing.
There is a lot of information in this discussion: