Block Unveils Dessa, a Full-Duplex Speech Model Trained Only on Speech

Block announced on October 23, 2026 a research preview of Dessa, a full-duplex speech-to-speech model trained only on human conversation audio, with no text and no pretrained models. Block says it trained Dessa on one NVIDIA GB200 NVL72 rack and that it runs locally on a MacBook Pro M4 Max or better, faster than real time. No benchmark scores, parameter count, weights, paper, API or price have been published, and access is via a waitlist.