Updated October 25, 2026.

Dessa AI is a conversational speech model developed by a research team at Block, the company co-founded by Jack Dorsey. It is designed to listen and speak in real time, including while the other speaker is still talking. The team announced it on October 23, 2026 (UTC). Dessa team announcement

The interesting part is how it learned. Block says Dessa was trained entirely on human conversation audio, without text or pretrained models. That makes it an experiment in learning language through sound. Block's Dessa research preview

This guide explains that approach, what the demos show, how Dessa AI compares with ChatGPT Voice, and what you can actually access today.

1. Why do words alone miss part of a conversation?

Imagine a friend says, "Oh, great."

With a bright voice, it might mean good news. After a long sigh, the same words could mean the opposite. A transcript can preserve the sentence while leaving you to guess what the speaker meant.

Timing matters too.…