Tuesday's I/O keynote included a segment on Google Assistant with a slew of newly announced features, but none was as startling as its rollout of Google Duplex: a voice-powered service that pretends to be human and calls businesses on your behalf.

Google CEO Sundar Pichai played back two phone conversations that he alleged were 100-percent legitimate, in which Google's AI-driven voice service called real-world businesses and scheduled appointments based on a user's data. In both cases, voices that sounded decidedly more human and realistic than the default female Google Assistant voice used seemingly natural speech patterns. Phrases like "um" and a decidedly West Coast question-like lilt could be heard as Google Duplex confirmed both a salon appointment and a dinner reservation. (The two calls were completed with different voices: one male, one female.)

"We are still developing this technology," Pichai told the I/O crowd, and he admitted many calls in Duplex's testing phase "didn't quite go as expected." (Pichai did not play any sample audio of these failed tests.)

Pichai says the service will also automatically call businesses during holidays and special events to discover whether shops will be opened or closed and update Google's listings accordingly. That part of Duplex's service will launch "as an experiment in the coming weeks." The fuller Duplex service did not receive as formal a launch window.

[Update, 3:05 p.m.: After I/O's conclusion, a lengthy breakdown of Duplex went live at the Google Blog. The post includes more sample Duplex calls, including a Google attempt to confirm hours of operation, as previously described in Pichai's speech, along with apparent successes in responding to interruptions. One call's audio, at the bottom of the blog post, includes more awkward and sometimes even rude-sounding speech and tone from Duplex's robotic speakers than in other examples, but the text doesn't acknowledge this disconnect.]

Another Google Assistant option, dubbed "Pretty Please," will debut "later this year" as an option that can be toggled on a per-device basis. It will, quite simply, require that users say "please" when issuing a voice command before Google Assistant will respond to it. The I/O presentation included a brief video of families using home Google Assistant devices and laughing while checking each other's politeness.

This goes one further than Amazon's Echo line of devices, which will roll out a "politeness affirmation" option tomorrow, May 9, dubbed the "magic word" feature. Amazon's version will simply offer affirmation when a user adds "please" to a search query.





Additionally, Google Assistant will soon receive a "continued conversation" option that users can elect to toggle. This will allow Google Assistant to continue listening to users after a question has been answered for the sake of follow-up queries. The idea being, people with many repeat queries will be able to ask multiple questions in a row, often sandwiched together. Google's Scott Huffman explained that, in many cases, "and" qualifiers can be inserted into questions to ask two things at once, though not always separated as two clean, separate phrases. The continued conversation system will take these into account, along with brief conversational phrases between questions.

And more voices are coming to Google Assistant, with six new American-accented voices coming "as of today." Pichai introduced the new voices, who all greeted the crowd (though the final voice robotically pronounced Pichai's name). He emphasized that real-voice recordings were used and processed by Google's "Wavenet" system, which he also showed being used by singer John Legend—whose own voice will be used in a Google Assistant feature "later this year."