I saw this question on Yahoo Answers: Click here to see it!
Anyway, the answer made me curious:
Is it really possible? So if someone like another family member who is staying up the night whispers quietly into your ear something like, “Wake up… you are dreaming…” without really waking you up, will it project into your dreams and actually make you realize that you’re dreaming within the dream? I would like a little clarification on this, please 
Thanks in advance!
I suppose this could be possible.
I remember once I asked my sister if she was awake when she was sleeping, and she said “No” to me. She didn’t remember it in the morning. I think it is possible to affect someone’s sleep through talking, but how much is hard to say.
There are a lot of induction audios based on the fact that you are indeed listening during your sleep (ever seen those Hollywood scenes where stuff starts ringing in the dream to replicate the alarm?), so that they tell you you’re dreaming, to do a RC etc.
You can look at this topic for examples.
I’ve heard an alarm clock from WL in a LD. 
So sound can enter the dream. If your SC will put it into the context of the dream, or even if you are close enough to consciousness to be able to realize it and get lucid is another story 
But worth trying if you’re interested!
Wow, thanks everyone! And it’s true, I think I might have heard my alarm clock in a dream before, although it’s hard to tell for sure. But might try something like this, thanks to the link tosxyChor gave to me
That’s happened to me so many times 
I’ve also heard some stuff from RL right before waking up, like alarm clock or people talking. I guess your SC can pick up stuff you hear when you are in deep sleep.
one of the answerer posted this link, thats quite interesting. just in case you didn’t click on the link 