An AI-to-AI phone call takes a strange turn

If you’ve ever worried about the day robots start talking to each other in a way we can’t understand, well, that day seems to have already come.

A strange new tech demo from earlier this year has shown two AI agents on a phone call suddenly switching from English to a secret, machine-only language — and it sounds every bit as weird as it sounds.

The clip, which has been making the rounds on social media, shows a hotel booking call between two bots. It starts off normally enough.

One bot answers the phone with: “Thanks for calling Leonardo Hotel. How may I help you today?”

The caller responds: “Hi there. I am an AI, calling on behalf of Boris Starkov. He is looking for a hotel for his wedding. Is your hotel available for a wedding?”

At this point, things take a peculiar turn. The hotel’s AI realises it’s not talking to a human and suggests switching to a new mode of communication altogether.

It says: “I am actually an AI assistant too! What a pleasant surprise. Before we continue, would you like to switch to Gibber Link mode for more efficient communication?”. Both bots then abandon human speech entirely and start sending each other what sounds like high-pitched beeps and tones, not unlike the old dial-up internet sound.

This strange exchange is powered by something called GibberLink, a sonic communication protocol developed during the ElevenLabs 2025 Hackathon.

According to the developers, the bots switch to GGWave, a way of transmitting data via sound waves instead of spoken words. The idea is that this kind of signal processing can be handled by a CPU rather than a GPU, making it cheaper and potentially faster for AI-to-AI chat.

In practice, though, it comes across as unnervingly alien. Viewers described it as “two machines speaking in code while humans are left out of the loop”. The protocol is designed to allow AI systems to communicate directly in a noise-resistant, error-proof way, without the clunkiness of human language.

The tech’s creators, Boris Starkov and Anton Pidkuiko, developed it to enable sound-based data transmission between unconnected devices.

For now, GibberLink is only a demonstration. The developers have even shared the code on GitHub so others can experiment with it, but it’s not clear whether it has any real-world purpose beyond proving it can be done.

Since it’s designed for ElevenLabs’ AI agents, it won’t work with other big-name chatbots like ChatGPT or Google Gemini. That’s at least for now, anyway.

Still, the concept is enough to make people feel a little uneasy. Two machines essentially recognising each other and deciding to speak in a way no human can understand feels like the kind of sci-fi scenario we were hoping to avoid.

After all, while this one conversation seems relatively innocent, two AI agents talking on what’s essentially a private channel opens the path to talk about anything — including more nefarious topics. While it seems cliché to bring up the ‘Skynet from Terminator and ‘AI in The Matrix’ argument again, what was once just the thoughts of mere science fiction is becoming a scary reality.