I was in my car today, and pressed my makeshift bluetooth Siri button to make a call. "Call David Wehrs" I said. But I heard myself pronounce my friend's last name with a rather awkward accent, drawing out the H, and I wasn't sure why. Until I heard Siri repeat back to me, "Calling David Wehhhrs". I had said my friend's last name the same way that Siri had repeated it back to me many times before.
I wonder if the software engineers working on these text-to-speech interfaces consider that the pronunciation that results from their many lines of code can change the way that people actually speak. With Apple alone predicted to sell over 1 billion iOS devices by 2015, this seems like a subtle eventuality.