Apparently, Google is using human aid to power its automatic-calling service Duplex, as a new report by The New York Times just revealed.

Duplex is an artificial intelligence-powered assistant that makes life-like calls for reservations on users' behalf. Google demonstrated how it works not too long ago, itself an impressive act of showmanship that put the company squarely at the forefront of AI innovation. That's not to say there were ever any doubts over Google's expertise in the field. Most, if not all, agreed that Duplex calls sounded eerily human.

But that's only because, as it turns out, 25 percent of all Duplex calls actually had humans behind them, as Google confirmed to The New York Times.

Google Duplex Uses Humans

According to Google, a quarter of Duplex calls begin with humans calls, and 15 percent start with AI and are later intervened by a person from the Duplex call center. Google told the publication that it uses a variety of signals to decide whether a call should be made by a human or AI. If the company is unsure of whether the business takes reservations, Google might decide to let a human make the call. Same goes if the user of the assistant might be a spammer.

Humans Are Temporary

Duplex works by attempting to make reservations with establishments that offer online booking tools, including Resy, Yelp, or OpenTable. If those aren't available, Duplex will take matters into its own hands and invoke AI. Google said it's still using human callers because the technology is young and uses that data to train its AI and eventually erase humans from the process altogether.

During a demo last year, Google said humans would be monitoring the system, so this news should perhaps come as no surprise. These humans, the company said at the time, would be ready in case something goes wrong. Duplex is now available on compatible iOS and Android devices, and this kind of testing should be expected for such a new technology. Still, as TechCrunch notes, 25 percent of calls being aided by actual humans seems a little too high for the advanced AI system.

Right now, it's clear Google has a lot of work to do, and a lot of data to collect, for that matter. Duplex has impressed a lot of folks with what it can do, but the underlying neural network must be fed tons of data to improve.