Artificial voices must have improved a lot in the past 2-3 years. None of the ones I've ever heard would pass muster. Something weird in their intonation, a kind of sameness or monotony in their speech i.e. lack of excitability, a bit too perfect and precise.

I just went to cereproc, one of these companies advertising a very realistic synthetic voice, and none of their voices convinced me at all, though I have to admit it was pretty good.

When they get so good that they are indistinguishable except through Turing tests, and maybe not even then, we'll all be in trouble. I somehow expect that we haven't yet reached that point, though it can't be long in coming.