Duplex, Google's human-like artificial intelligence debuted last summer, is now available for all Pixel smartphone owners in 43 US states.

A feature added to the Google Assistant, Duplex can be used to make a restaurant reservation on your behalf. All you have to do is open the Assistant on your Pixel smartphone and say something like: "Book a table for two people at [restaurant name] tomorrow night."

Read More:

• This is how Google Duplex AI works to make phone calls on your behalf
• Will Google Duplex replace call centers?
• Hello, AI speaking: Google Duplex will identify itself as non-human

The Assistant will then make the call, speak with the staff member using a realistic human-sounding voice, and let you know with a notification that the reservation was a success. The Assistant also automatically emails you about the reservation and adds it to your calendar.

Google first showed off Duplex last summer, before rolling it out to a small number of users in a handful of US cities in October. Now, just a few months later, the system can be used in 43 states.

Although limited to Google's own Pixel smartphones for now, the company says it has plans to bring Duplex to many more people across the US soon. "Over the next few weeks, we'll start slowly bringing this feature to more Android and iOS devices, and will continue to incorporate feedback as we continue testing."

Once you have told the assistant what you want from the booking - the restaurant name, size of the party, and preferred date and time - the assistant makes the call on your behalf and completely without your involvement. Google has demonstrated how the voice sounds like a real human and can navigate fairly complex conversations, dealing with unexpected questions and adjusting the booking time slightly if necessary.

The assistant introduces itself by saying it is "calling from Google" and informs the restaurant that the call may be recorded. It also uses 'ums' and 'erms' to sound convincingly human and not at all like a robot.

Although Duplex can only make restaurant reservations for now, Google's first demo of the technology, back in June 2018, showed how it could also be used to make an appointment at a hair salon. Therefore, it is likely that Google will offer more abilities in the near future.