Model Architecture — Access the Architectures Behind Leading Voice Models | Hume AI | Hume AI
Model Architecture
Leapfrog years of R&D. Access the architectures behind leading voice models.
Don't solve every problem from scratch. At Hume, we believe the best voice AI is built through collective effort.
TADA
Low latency, low hallucination, open source
Deploy TADA (Text and Audio Dual Alignment), a TTS system with text and audio in one synchronized stream to reduce token-level hallucinations and improve latency.
Features
- Zero hallucinations: Zero content hallucinations across 1,000+ test samples.
- 5x faster: 5x faster than similar-grade LLM-based TTS systems.
- Long-form audio: 2,048 tokens cover ~700 seconds with TADA vs. ~70 seconds in conventional systems.
- Free transcript: Get a transcript alongside audio with no added latency.
- MLX support: Run locally on Apple Silicon with optimized MLX inference.
- Open source: Fully open weights and architecture for research and production.
EVI
Empathic speech to speech with contextual understanding
Access EVI (Empathic Voice Interface), a speech to speech system with user speech prosody understanding, native language generation, and customizable voices.
Features
- Emotion instruction: Emotion instruction following and unparalleled naturalness.
- Voice design: Voice cloning and voice design support.
- Natural turn-taking: Interruptibility and back channeling.
- Tool use: Tool use and dynamic variables for agentic workflows.
- Context injection: Context injection and external LLM compatibility.
- Multilingual: Native language generation across a growing list of languages.
Octave
Low latency TTS with voice design and expression modulation
Use Octave (Omni Capable Text and Voice Engine), an LLM-based TTS system with voice design, voice modulation, voice cloning, voice conversion, and more.
Features
- Multispeaker: Multispeaker and multilingual synthesis in a single model.
- Voice design: Infinite voices through natural language voice descriptions.
- Creator platform: Purpose-built for audiobooks and podcasts.
- Voice cloning: Clone any voice from a short audio sample.
- Expression modulation: Fine-grained control over emotion and delivery style.
- Low latency: Streaming output with fast time-to-first-byte for real-time use.
From Our Lab
Peer-reviewed insights
RW-Voice-EQ Bench: A Real World Benchmark for Evaluating Voice AI Systems
Current voice AI benchmarks typically evaluate isolated capabilities such as speech intelligibility, word error rate, or text-based dialogue quality, but they rarely test whether systems harness the acoustic information that distinguishes spoken language from its textual representation. To this end, we introduce the Real World Voice EQ Bench, a multidimensional benchmark for evaluating voice AI across text-to-speech (TTS), speech-to-speech (STS), speech understanding (SU), and automatic speech recognition (ASR). Our evaluations indicate that performance is highly dimension-specific. For TTS, naturalness, expressiveness, identity stability, and reliability are largely independent evaluation dimensions. For STS, access to audio does not guarantee use of vocal affect, and some agents remain largely transcript-driven. For SU, models perform unevenly across paralinguistic tasks. For ASR, real-world accent, emotion, noise, and conversational conditions expose failures that are not captured by established clean-speech benchmarks. Together, these results show that voice AI should be evaluated as a profile of acoustic, expressive, interactional, and robustness capabilities rather than by a single aggregate score.
The 2026 ACII Dyadic Conversations (DaiKon) Workshop & Challenge
The 2026 ACII Dyadic Conversations (ACII-DaiKon) Workshop & Challenge introduces a benchmark for modeling interpersonal affect and social dynamics in dyadic conversations. Although conversational affect modeling has advanced rapidly, most benchmarks remain speaker-centric and underrepresent coupled, time-evolving processes between partners, including directional influence, conversational timing coordination, and rapport development. To address this gap, ACII-DaiKon presents three coordinated sub-challenges built on a shared dataset: (1) directional interpersonal influence prediction, (2) turn-taking prediction (next-speaker and time-to-next-speech), and (3) rapport trajectory prediction across full interactions.
The challenge is built on the Hume-DaiKon dataset, comprising 945 dyadic conversations (743.4 hours of audiovisual data) collected under naturalistic conditions across five languages. The benchmark supports multimodal modeling, temporal reasoning, and cross-context generalization through fixed train/validation/test splits, standardized metrics, and released baseline systems. Evaluation uses Concordance Correlation Coefficient (CCC), Pearson correlation, Macro-F1, and Mean Absolute Error (MAE) depending on the sub-challenge.
TADA: A Generative Framework for Speech Modeling via Text-Acoustic Dual Alignment (Under Review)
Modern Text-to-Speech (TTS) systems increasingly leverage Large Language Model (LLM) architectures to achieve scalable, high-fidelity, zero-shot generation. However, these systems typically rely on fixed-frame-rate acoustic tokenization, resulting in speech sequences that are significantly longer than, and asynchronous with their corresponding text. Beyond computational inefficiency, this sequence length disparity often triggers hallucinations in TTS and amplifies the modality gap in spoken language modeling (SLM). In this paper, we propose a novel tokenization scheme that establishes one-to-one synchronization between continuous acoustic features and text tokens, enabling unified, single-stream modeling within an LLM. We demonstrate that these synchronous tokens maintain high-fidelity audio reconstruction and can be effectively modeled in a latent space by a large language model with a flow matching head. Moreover, the ability to seamlessly toggle speech modality within the context enables text-only guidance--a technique that blends logits from text-only and text-speech modes to flexibly bridge the gap toward text-only LLM intelligence. Experimental results indicate that our approach achieves performance competitive with state-of-the-art TTS and SLM systems while virtually eliminating content hallucinations and preserving linguistic integrity, all at a significantly reduced inference cost.