I can't speak to the training of the models. I'm not a data science guy, I specialize in signal processing and feature extraction. What I can say, though, whic

I can't speak to the training of the models. I'm not a data science guy, I specialize in signal processing and feature extraction. What I can say, though, which may give good insight into your question is this: The "Hushpuppy" project, which became known as the WhisperSync and Immersion Reading technologies, were not self-trained or self-reinforced. QA engineers in India were contracted to ensure synchronization between the book and the audiobook. These technologies, though, were the building blocks upon which Alexa was developed. The data collected from these operations became essential knowledge for the engineering team that developed Alexa. EDIT: As an aside, Amazon bases all of its services around that Amazon account that almost everyone in the civilized world now has. Alexa is not the first, and certainly not the last Amazon service that learns and improves based upon the user's Amazon account.