Might try this over the weekend. The recording of people talking would probaly be that of someone with a low toned voice or soft voice so it's not loud or (not high pitched, high toned?can't think of the word)to disturb your dreaming or anyone else's sleeping.
It would also come down to getting the timing correct, since some people don't remember they're dreaming during the earlier stages of sleep, getting it timed towards the second or last stage would be best. Instead of trying to figure out the time you're sleeping or whatever, make it less complex and just have it as a timer(as stated before). Maybe make it go off around 4 hours into dreaming. Even something as simple as someone saying "You're dreaming" would work(it would have to repeat a few times since it's human nature to question what someones saying(in a dream it would most likely be.)
Sorry if I didn't make any sense, quite tired.