Mar 28, 2017
The voice recognition system in the iPhone operates entirely on the basis of acoustic physics, not at all on linguistic phonetics. It attempts to match sounds with signal types that it has been trained to respond to in certain ways, but beware of imagining that it knows when you are saying something, or even what "saying something" means. The truth is that it cannot tell the difference between a labiodental fricative and an anal fricative. Let alone distinguish between when you're saying something sensible and when you're talking out of your ass.
Geoffrey K. Pullum, “Siri and Flatulence”