❯ Block unveils Dessa, a real-time speech model trained only on human conversation

Learning conversation from soundOn October 23, Block’s research team unveiled Dessa. The company says it was trained from scratch exclusively on human conversation audio, without text or pretrained models, and can listen and speak simultaneously in real time. It published live conversation recordings and invited a small group of AI safety researchers to obtain early access.

Learning timing as well as toneFull-duplex interaction allows both sides to transmit and receive audio simultaneously. Block emphasizes pauses, interruptions, brief acknowledgments and emotional delivery. Stress, sighs and laughter can change a sentence’s meaning. Learning those signals directly may improve aspects of interaction that text alone does not capture.

The demonstrations need broader testingThe team says Dessa can run locally on a MacBook Pro with an M4 Max or better, but has not published a comprehensive evaluation establishing overall comparative performance. Its immediate contribution is a speech-native training approach that can be tested further. Conversational timing, knowledge and risk behavior require separate assessment in broader use.

▮ SIGNALSpeech-native models treat conversational timing and vocal emotion as learning targets, calling for evaluation beyond transcription accuracy.