[alias_neo]

No, they don't, however, accidental activation is still highly likely.

I've had other people's devices activate during conversations where I couldn't figure out which part of the sentence activated them, it just happens.

"Ok, Go get..." "Ok, Good ..." "All except..." "Sir, I..."

Then you have television shows and adverts that intentionally use language to activate these assistants.

Usually the assistants are going to say something when it accidentally detects a wake word, but if you're in another room or don't hear it for some reason, it can easily capture a conversation without you knowing.

[freehunter]

I use the phrase “are you serious?!” a lot when I am frustrated. Almost always it wakes up Siri on at least one of my iDevices. Which makes me say “are you serious?!” again and it just spirals from there.