Block unveils Dessa, a full-duplex speech model trained only on conversation
Block
Jack Dorsey's Block announced Dessa on October 23, 2026, a speech-to-speech model built from scratch on recorded human conversation with no text data and no pretrained backbone. It is full-duplex, listening and speaking simultaneously, was trained on a single NVIDIA GB200 NVL72, and runs locally on a MacBook Pro M4 Max or better. Access is waitlist-only, with limited early access for AI safety researchers; Block did not disclose parameter count.
Why it matters
A frontier voice model trained on audio alone, without a text LLM underneath, is a direct challenge to the text-first recipe every major TTS and realtime-voice vendor currently uses.
Importance: 4/5
new model class from a major platform
Sources
official
Dessa — Block