A YouTube video sent to Apple blog 9to5Mac lets you hear the difference between the old Siri and the new one. In the video, a more lifelike Siri says certain words much more naturally, as if they were recorded by an actual person. The digital assistant's cadence has also improved, as the pitch of Siri's voice drops at the end of clauses just like a natural English speaker's would. Siri's voice has undergone periodic tweaks and fixes, but none so major as when Apple (AAPL, Tech30) released iOS 7 in 2013. In that update, Siri got an entirely new sound, switching from actress Susan Bennett's voice to two other unnamed actors (one male and one female).