Block's Dessa Voice AI Learned to Talk From Speech Alone — and It Sounds Human
Jack Dorsey’s payments company Block has built a voice AI that never learned to read. On October 23, 2026, Block unveiled Dessa, a speech model it says was trained from scratch on nothing but recorded human conversation — no text, no pretrained models, no transcription step in between. The result, in Block’s own demo recordings, is unsettling. Dessa laughs mid-sentence. It cuts in. It sounds tired when it says it’s tired from work. Dorsey called it “the most authentic full-duplex speech model ever built” in a post on X, adding that “talking with it feels like talking with a person… full of emotion, nuance, pauses, and a natural cadence.” ...