Absolutely! I fell asleep watching something on the discovery channel once (can't remember what it was about)...had a dream about floods...woke up and there was a program about "the great flood" on the t.v. I have also purposely played a particular song on low volume as I slept...and trained myself to perform a RC when I heard it and became lucid (only did it once successfully, but haven't tried it a whole lot to be honest). Using an outside influence to induce lucidity is known as an EILD (externally induced lucid dream).