[incone123]

Depends on the movie. Ash and Bishop in the Alien franchise sound human until there's a dramatic reason to sound more 'robotic'.

I agree with your wider point. I use Google TTS with Moon+Reader all the time (I tried audio books read by real humans but I prefer the consistency of TTS)

[regularfry]

Slightly different there because it's important in both cases that Ripley (and we) can't tell they're androids until it's explicitly uncovered. The whole point is that they're not presented as artificial. Same in Blade Runner: "more human than human". You don't have a film without the ambiguity there.

[incone123]

You're right. I should have used Marvin from Hitchhiker's Guide as an example instead. There's very light processing on his speech.