Reading your comment I just tried and also got 100%. There are more micro-pitch variations, vibrato and harmonics in the human voice; the robot voice kind of sounds the same, but on some short sounds sometimes produces a kind of monocord sound that is not only non-human, but probably impossible for a human to imitate.

It seems some people are more sensitive than others to robot-sounding or robot-looking. I have a very hard time watching modern movies because most special effects completely ruin the experience for me; but other people seem to not mind at all.