Block unveils Dessa, a “true speech-to-speech” AI model trained on “nothing but human conversation” that it says runs locally on a MacBook Pro M4 Max or newer

The Verge 2026-10-26 Jay Peters

Context & Ripple Effects

Dessa extends a progression from Google's dialogue-focused LaMDA to speech systems such as Microsoft's VALL-E voice-simulation model. Microsoft's 2025 MAI-Voice-1 emphasized rapid audio generation on a single GPU; Block is instead positioning speech-to-speech interaction and stated local execution on a MacBook Pro M4 Max or newer as the differentiators.

The story also arrived with unusually broad pickup and public concern over convincing AI voices being used for scams. Those reactions make trust and caller disclosure central adoption questions, not merely model-quality issues.

First-order effects

Block gains a concrete client-hardware deployment target for Dessa: a MacBook Pro M4 Max or newer, rather than an unspecified server environment.
Block must address the scam concerns raised around highly convincing synthetic speech as it promotes Dessa's conversational realism.

Second-order effects

Microsoft's MAI-Voice-1 and other speech-model efforts face comparison not only on generation speed or voice imitation, but on whether they can support natural speech-to-speech exchanges on accessible hardware.
MacBook Pro M4 Max becomes a relevant reference point for developers evaluating whether advanced voice interaction can be deployed on-device rather than solely through GPU-backed services.

Third-order effects

If locally runnable speech-to-speech models become common, voice interfaces may compete on conversational turn-taking and trust signals rather than text-chat quality alone.
The associated fraud concerns point toward a conversational disclosure stack in which providers need ways to distinguish synthetic voices from human callers.

The trend: AI voice is moving from text-mediated assistants and standalone voice generation toward full-duplex, device-capable conversational systems, with authenticity and disclosure becoming part of the product challenge.

Discussion

@jack @jack on x
We believe voice is the most natural way to interact with intelligence, so we created Dessa, the most authentic full-duplex speech model ever built. Talking with it feels like talking with a person...full of emotion, nuance, pauses, and a natural cadence. https://block.xyz/dessa
@simonlerouxx Simon Le Roux on x
Another fun dessa sample featuring @dvirzg @CashApp https://block.xyz/dessa [video]
@alymoursy Aly Moursy on x
bro my parents are so cooked https://block.xyz/dessa
@linusekenstam @linusekenstam on x
This breakthrough from Block with Dessa is something I believe we will see more and more of in the coming months. As the field matures, more and more novel approaches to training based on simple human curiosity will lead to unimaginable tools and discoveries. dessa was trained on…
@ragavanthurair Ragavan Thurairatnam on x
Meet Dessa, our AI model trained from scratch on nothing but speech. We believe speech is the natural interface for technology. So we built Dessa. And we're inviting AI safety researchers to explore Dessa. Learn more: https://block.xyz/dessa
@shivaroor Shiv Aroor on x
Scam calls about to attain pandemic level.
@kimmonismus @kimmonismus on x
Seriously mindblowing: This voice model runs locally on an M4 Max Mac or better. Feels like magic. [video] [embedded post]
@trackingcosts @trackingcosts on x
Scam calls about to get to next level. Never pick up your phone again. [embedded post]
@cz_binance @cz_binance on x
This might be very good for @GiggleAcademy. Teaching kids in current “AI voice” was a challenge. [embedded post]
@linusekenstam @linusekenstam on x
I'm shook OpenAI voice just got slapped hard I'm in complete disbelief that this new voice model is made by Block and not Elevenlabs et al. I mean Jack literally took it to 11 and solved the turing test for voice. you'll never know if you're talking to a machine or human. [video]…
@layoffai @layoffai on x
What in the black mirror has Jack Dorsey done?
@justinebateman Justine Bateman on x
Lol, why? If your AI agents can do everything advertised, why not keep the voice fairly robotic? What is the reason to trying so hard to make these “voices” sound as human as possible? Deception. Any why would you want that? So you can trick people into lowering their guard and l…
@kimmonismus @kimmonismus on x
Jack Dorsey released a speech model that sounds best in class. But even more interestingly, it was trained on only one NVIDIA GB 200 NVL72 [image] [embedded post]
@templetonthomas Thomas Templeton on x
words matter. so does everything between them. really excited about what the team is building with dessa. https://block.xyz/dessa
@arpagon Sebastian Rojo on x
What a legit team @blocks (@jack) put behind Dessa. @RagavanThurair @RayhaneMama @carajzp @dvirzg. • RealTalk (2019): the Joe Rogan voice clone • Efficient-VDVAE • Tacotron-2, 2.3K★ Now: full-duplex speech-to-speech trained only on raw speech.
@simplykashif Kashif Raza on x
Jack Dorsey's Block has just unveiled Dessa, an AI speech model that sounds so human that you might not even realize you're talking to a machine. Imagine scammers using voices like these. How will we know who to trust anymore?👀
@jack @jack on x
only cash app
@amritaahuja Amrita Ahuja on x
Exploring new approaches to speech AI, including how models can learn directly from human speech and better understand the nuance of conversation, is more relevant than ever. Proud that @blocks culture creates space for small teams like Dessa to innovate.
@blocks Block on x
For the love of the game. Watch Cara play a guessing game with Dessa. The model guesses the first one right straight away, and the second doesn't take long either. https://block.xyz/dessa [video]
@blocks Block on x
Calling all AI safety researchers. We're inviting a small group to explore Dessa, our model trained on speech alone, and help us understand what it can and can't do. We'd love to hear from you: https://block.xyz/dessa [video]
@testingcatalog @testingcatalog on x
Jack Dorsey announced a new full-duplex speech model, called Dessa. Dessa was trained solely on voice conversations, with no text data or pretrained models. Currently, only demo samples are available, but they far surpass anything else in emotional expression and natural feel. Vo…
@chrisparkx Chris Park on x
This is the most human voice AI I've heard. Good job in capturing real human feel, even the laughs and random pauses we all do when we're thinking. Block & Dessa team cooked. Well done!
@naithanjones Naithan Jones on x
I now see the danger in “humanizing” AI with human names and human qualities. Millions of people do not have the cognitive sophistication to handle this and millions will have deep AI psychosis in five years. I believe AI should be presented in a sterile UI as much as possible
@davetist Dave on x
this is fucking insane and my expectations about ai psychosis have scalated exponentially after listening to the samples it's truly over
@axhoff Alexander Hoff on x
please listen to dessa. i have never heard anything artificial that sounded so... human. if you ever doubted that human-ai-relationships were going to be a thing. well. this snippet will convince you otherwise.
@bffmike Mike Manzano on x
Holy crap this runs LOCALLY on a Mac
@gregoryconti19 Gregory Conti on x
This project of making machines imitate humanity ever more closely strikes me as an evil and dangerous enterprise that society should at least stigmatize and probably outlaw.
@thebitsian @thebitsian on x
Pretty scary stuff. Black mirror incoming.
@fasterthanli.me Amos Wenger on bluesky
block.xyz/dessa — Yeah this is gonna do more damage than GPT-4o 🫠 — It's truly impressive stuff, don't get me wrong, but Jesus Christ, if you think people had AI psychosis before now...
@mk.gg Matt Kane on bluesky
This is the best speech model I've heard by some margin, and it is seriously dangerous. If they release it like this, people are going to be falling in love with this model, and their choice of samples does not inspire confidence that they're taking the possibility of this serio…
r/programiranje r on reddit
AI speech modeli definitivno idu na sledeci nivo

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