Dessa
Dessa is Block's speech-to-speech artificial intelligence model for conversational voice research and applications. It takes audio input and produces audio output directly, without converting speech into text as an intermediate step. Trained from scratch on human conversation rather than text, the model supports full-duplex interaction, listening and speaking at the same time, and runs locally on a MacBook Pro with an M4 Max chip or better. It captures conversational cues such as emotion, sarcasm, laughter, pauses, and turn-taking that can be lost in text-based pipelines. Dessa is intended for AI safety researchers and developers studying voice-model behavior, privacy, and real-time interaction. It is a speech model for research and development, not a general-purpose business application or hosted voice-agent platform.
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Voxtral TTS
Voxtral TTS is a state-of-the-art, multilingual text-to-speech model designed to generate highly realistic and emotionally expressive speech from text, combining strong contextual understanding with advanced speaker modeling to produce natural, human-like audio output. Built as a lightweight model with around 4 billion parameters, it delivers efficient performance while maintaining high quality, enabling scalable deployment for enterprise voice applications. It supports nine major languages and diverse dialects, and can adapt to new voices using only a short reference audio sample, capturing not just tone but also rhythm, pauses, intonation, and emotional nuance. Its zero-shot voice cloning capabilities allow it to replicate a speaker’s style without additional training, and it can even perform cross-lingual voice adaptation, generating speech in one language while preserving the accent of another.
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Voxtral Mini TTS 3.0
Voxtral Mini TTS 3.0 is Mistral AI's text-to-speech model for developers building voice-enabled applications and services. It generates speech from text in batch and real-time workflows, with preset or cloned voices, emotion and pace controls, and custom pronunciation. The model supports multilingual speech generation and dialect adaptation, making it suitable for conversational audio, localized content, spoken responses, and voice agents. Developers can access speech generation and voice-cloning capabilities through Mistral's API. Voxtral Mini TTS 3.0 is also part of Mistral's Voxtral 3 voice-agent stack, which combines speech recognition, reasoning, tool use, and generated speech; the Voxtral 3 stack can be self-deployed on customer infrastructure.
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Eleven v4
Eleven v4 is a text-to-speech model from ElevenLabs for generating expressive spoken audio from written scripts. It supports multi-speaker dialogue, emotional direction and audio-event tags, voice cloning, and consistent speaker identity across generated scenes. Creators, publishers, and production teams can use it for narration, audiobooks, character dialogue, video and game voiceovers, and multilingual projects. Developers can generate speech through the ElevenLabs web application or API; the related Eleven v4 Turbo model is intended for real-time speech and voice-agent scenarios. Eleven v4 supports 90+ languages. A free plan includes monthly credits for personal use, while paid plans provide higher credit limits and additional features.
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