Block unveils Dessa, a speech-trained AI that converses like an awkward new acquaintance

Block, the company led by Jack Dorsey, has announced Dessa, an AI model built from scratch using only human conversation. To demonstrate it, the company shared sample chats in which the model sometimes sounds stiff or slightly eerie. One example, posted by Dessa lead Ragavan Thurairatnam, shows a mostly natural exchange, though the model initially confuses the speaker with someone named Ronaldo. Block describes Dessa as a full-duplex speech-to-speech model, meaning it can listen and respond in real time. The company presents it as a step toward more realistic voice-based AI conversations.