The trick, Amazon said, is the use of Neural Text-To-Speech (NTTS) technology that relies on deep learning to create the speech signal. The AI-based system learns to both intonate more effectively and emphasize the right words in a sentence. This not only leads to more natural-sounding responses, but can adapt to a given context.

Get ready for more. Amazon described this as the "first step" in modifying Alexa's style to suit different requests, so you may hear the voice assistant adopt a wide variety of tones going forward. That could sound jarring at first if you're used to monotonous delivery from AI helpers, but Amazon is clearly betting that this will sound more natural (and ideally, more pleasing) in the long run.