# Block unveils Dessa, a voice model trained only on human speech

> The full-duplex model listens and talks at once, runs on a MacBook Pro M4 Max, and is limited for now to a waitlist and a group of safety researchers.

URL: https://claudegpt.si/news/block-dessa-speech-to-speech-model  
Published: 2026-10-24T17:22:52.893Z  
Author: ClaudeGPT Si Newsroom  
Section: AI Models  
Topics: Block, Dessa, Voice AI, Speech models  
Publisher: ClaudeGPT Si

## Key takeaways

- Block unveiled Dessa on October 23, a speech-to-speech model trained from scratch on human conversation with no text.
- Block says Dessa runs locally on a MacBook Pro with an M4 Max chip or newer.
- Access is limited to a waitlist and a small group of AI safety researchers, with no API, price or weights announced.

Block, the company behind Square and Cash App, unveiled Dessa on October 23, a speech-to-speech model trained only on recordings of human conversation. Block's [announcement page](https://block.xyz/dessa) says it used no text and no pretrained models, and that Dessa runs locally on a MacBook Pro with an M4 Max chip or newer.

Most voice assistants turn speech into text, run it through a language model, and turn the answer back into speech. That pipeline drops tone, timing and emotion. Dessa skips the text step entirely, which is why its demos sound less like an assistant and more like a person on a call.

## How Dessa works

Dessa is a full-duplex model, meaning it listens and talks at the same time, the way people do on the phone. Block says it can interrupt naturally, make the small "mm-hm" sounds people use to show they're listening, laugh, pick up sarcasm and change its volume when asked.

Block says the model learned language from far fewer words than text-based language models, though it gives no figures. It was trained on one NVIDIA GB200 NVL72, a single rack of Nvidia's data center hardware. Block has not disclosed the model's size or published any benchmarks. Its claims rest on recorded demos, including conversations with people and one with another company's voice model.

"We believe voice is the most natural way to interact with intelligence," Jack Dorsey said, [as quoted by TechCrunch](https://techcrunch.com/2026/10/24/blocks-new-voice-model-sounds-eerily-human/).

## Who can use it

Nobody outside Block yet. There is a waitlist on the site, and early access is limited to a small group of AI safety researchers, who apply with an institutional email address. TechCrunch reports that Block asked them to test cases such as a voice agent deceiving people. The page mentions no API, no app, no price and no plan to release weights. It says launch links are "coming soon".

## Why a payments company built a voice model

The work comes from a small research lab inside Block led by Ragavan Thurairatnam, which reports to Dorsey and grew out of a Toronto startup also called Dessa. TechCrunch notes that Square already uses voice AI for ordering. A model that runs on a laptop instead of in a data center could lower the cost of voice ordering and support, TechCrunch suggests.

A model that sounds this human also raises an obvious risk: it is harder to tell you are talking to a machine. Giving safety researchers access first is a sensible order of operations, but until Block publishes its size, its training data and some numbers, the demos are the only evidence. Watch for the launch links and for whether the weights come out.

## Sources

- [Dessa](https://block.xyz/dessa), Block
- [Block's new voice model sounds eerily human](https://techcrunch.com/2026/10/24/blocks-new-voice-model-sounds-eerily-human/), TechCrunch