Teaching virtual assistants new tricks: Why Google, Microsoft and Amazon love the sound of your voice

Amazon's Echo has made tangible the promise of an artificially intelligent personal assistant in every home. Those who own the voice-activated gadget (known colloquially as Alexa, after its female interlocutor) are prone to proselytizing "her" charms, applauding Alexa's ability to call an Uber, order pizza or check a 10th-grader's math homework. The company says more than 5,000 people a day profess their love for Alexa. On the other hand, Alexa devotees also know that unless you speak to her very clearly . . . I hate her, I love her," one customer wrote on Amazon's website, while still awarding Alexa five stars.