In early October, CNN revealed that veteran voice actor Susan Bennett was the voice behind Siri until Apple changed it in iOS 7. Her utterances, she revealed in an interview, were being used by the tech giant (and its likely voice synthesis partner Nuance) to generate the digital assistant's own words.Of course, even a company as technologically sophisticated as Apple is unlikely to have figured out a way to clone Ms. Bennett and place tiny copies of her inside every iPad and iPhone. Which makes for a question more fascinating than that of Siri's identity: How exactly is a person's voice transformed into a software program that can synthesize any text thrown at it?My voice is my passportIn Sneakers, a much underrated movie that seems oddly appropriate in today's er