Google’s AI assistant will identify itself as a robot when calling up businesses on behalf of human users, the company has confirmed, following accusations that the technology was deceitful and unethical.

The feature, called Google Duplex, was demonstrated at the company’s I/O developers’ conference on Tuesday. It is not yet a finished product, but in the two demos played for the assembled crowd, it still managed to be eerily lifelike as it made bookings at a hair salon and a restaurant.

But the demonstrations sparked concern that the company was misleading those on the other end of the conversation into thinking they were dealing with another human, not a machine. The generated voice not only sounds extremely natural, but also inserts lifelike pauses, um-ing and ah-ing, and even responding with a wordless “mmm-hmm” when asked by the salon worker to “give me one second”.

The social media theorist Zeynep Tufekci was one of many concerned by the demo. She tweeted that it was “horrifying” and described Silicon Valley as “ethically lost”.

zeynep tufekci (@zeynep) Google Assistant making calls pretending to be human not only without disclosing that it's a bot, but adding "ummm" and "aaah" to deceive the human on the other end with the room cheering it... horrifying. Silicon Valley is ethically lost, rudderless and has not learned a thing.

In its initial blogpost announcing the tech, Google said: “It’s important to us that users and businesses have a good experience with this service, and transparency is a key part of that. We want to be clear about the intent of the call so businesses understand the context. We’ll be experimenting with the right approach over the coming months.”

In a statement to the Verge, the company has confirmed that that will include explicitly letting people know they are interacting with a machine. “We understand and value the discussion around Google Duplex – as we’ve said from the beginning, transparency in the technology is important,” a Google spokesperson said. “We are designing this feature with disclosure built in, and we’ll make sure the system is appropriately identified. What we showed at I/O was an early technology demo, and we look forward to incorporating feedback as we develop this into a product.”

Google’s hope with Duplex is that it will enable a range of interactions with businesses that only have a phone connection, where this was previously limited to those with more hi-tech set-ups. The company envisages being able to call businesses to ask about opening hours then posting the information on Google; allowing users to schedule a reservation even when a business is closed, lining up the Duplex call for when doors open; and solving accessibility problems by, for instance, letting hearing-impaired users book over the phone, or enabling phone bookings across a language barrier.

The company said it would begin testing Duplex more widely “this summer … to help users make restaurant reservations, schedule hair salon appointments, and get holiday hours over the phone”.