Vangelis - Blush Response

Rachael: It seems you feel our work is not of benefit to the public.
Deckard: Replicants are like any other machine: they’re either a benefit or a hazard. If they’re a benefit, it’s not my problem.
Rachael: May I ask you a personal question?
Deckard: Sure.
Rachael: Have you ever retired a human by mistake?
Deckard: No.
Rachael: But in your position that is a risk…
Tyrell: Is this to be an empathy test? Capillary dilation of the so-called blush response… fluctuation of the pupil… involuntary dilation of the iris.
Deckard: We call it Voight-Kampf for short.