RA

Real-time avatars that change emotions as you talk

Hey HN, we're Ben and Caoimhe, cofounders of Anam. We build interactive avatars and just shipped our latest model, cara-4. This is the first avatar model which can naturally shift emotions and expressions during the conversation; a feature we’re calling “Director Notes”. The way it works is relatively simple: we have an LLM provide cues such as [laughter], [sad], [warm] interleaved with the speech, which we then condition our animation model with. To test it out, we commissioned a blind study from Mabyduck.com with 200 participants, 1,600 rated live interactions across six criteria. Cara-4 ranked first overall and was preferred head-to-head over each competitor on overall experience, lip-sync, visual quality and “naturalness”. On latency, measured across a full week of live traffic, end of user-speech to first video frame is ~1.2s median. The avatar model's own share is just ~100ms; most of the rest is waiting on STT, LLM, TTS or various forms of buffering (an unsung latency killer). How the model works: cara-4 has a two-stage design, a diffusion transformer turns audio+text into motion embeddings (head pose, gaze, lip shape, expression), and a rendering model applies those to a reference image, so new faces works without finetuning. Why faces at all: they carry emotional signal that text and voice don't, and they're a more accessible medium. Anam started in part from Ben watching his gran struggle with her iPad and thinking there should be a face she could just talk to. If you’d like to test it for free go to anam.ai