Speech Arena
Elo · text-to-speech arena
Octave 2 overview
Octave 2 by Hume AI
It comprehends meaning and emotion, delivering unparalleled voice quality and expressiveness.
Octave 2 specs
- Model ID
hume/octave-2- Developer
- Hume AI
- Input
- Text
- Output
- Audio
- Endpoint
POST https://api.aimlapi.com/v1/tts
Octave 2 API Overview
Octave 2 is the next-generation multilingual text-to-speech system, powered by large language model (LLM) intelligence. It understands text emotionally and semantically to generate expressive, human-like speech in real time. This system is designed to deliver industry-leading voice quality with ultra-low latency and broad language support, enabling versatile use cases from conversational AI to audiobooks.
Technical Specifications
- Supported Languages: English, Japanese, Korean, Spanish, French, Portuguese, Italian, German, Russian, Hindi, Arabic
- Voice Cloning: Supported (requires ~15 seconds audio)
Performance Benchmarks
- Octave 2 delivers 40% faster audio generation than Octave 1, with typical latencies under 200 milliseconds.
- In blind auditory tests involving 180 human raters comparing Octave to ElevenLabs Voice Design, Octave was preferred for audio quality (71.6%), naturalness (51.7%), and matching voice descriptions (57.7%).
- The model reliably handles emotional shifts and complex speech patterns, improving overall naturalness and expressiveness.
Key Features
- LLM-powered Emotional Understanding: Unlike traditional TTS, Octave 2 interprets the meaning and emotional intent behind text, modulating pitch, tempo, and emphasis to match context.
- Ultra-low Latency: Real-time speech synthesis with model latency as low as ~100 milliseconds, ideal for interactive and conversational applications.
- Multilingual Support: Fluent synthesis in 11 languages including English, Japanese, Korean, Spanish, French, Portuguese, Italian, German, Russian, Hindi, and Arabic.
- Long-Form Versatility: Maintains emotional consistency across extended content such as audiobooks and podcasts, adapting seamlessly to changes in character emotions or scenes.
- Advanced Features: Voice conversion, direct phoneme editing, and reliable pronunciation of uncommon or repeated words, numbers, and symbols.
Comparison with Other Models
vs ElevenLabs: Octave 2 uses LLM intelligence to deeply understand and express the emotional and semantic context of text, producing nuanced speech with real-time latency around 100ms. ElevenLabs offers highly natural and expressive voices with real-time streaming but lacks the advanced semantic understanding and broader multilingual support found in Octave 2.
vs OpenAI TTS: OpenAI's TTS focuses on clarity, prosody control, and interactive real-time streaming, enabling flexible speaking styles via prompts. Octave 2 expands on this by integrating emotional intent recognition at a semantic level, leading to more human-like expressiveness.
vs Mozilla TTS: Mozilla TTS is highly customizable and favored in research for building custom voices but is often less performant in real-time responsiveness and emotional expressiveness. Octave 2, as a commercial-grade LLM-based system, delivers superior voice quality, faster synthesis, and more natural emotional modulation out of the box.
vs Chatterbox: Chatterbox is optimized for low-latency dialogue and configurable expressiveness with efficient voice cloning at a smaller model scale. Octave 2 surpasses Chatterbox in semantic understanding and emotional depth, offering a richer real-time voice experience with longer-form consistency and multilingual capabilities.
Use cases
- Conversational AI and Interactive Agents: Real-time, emotionally aware speech for chatbots, virtual assistants, and customer service.
- Audiobooks and Podcasts: Long-form narration with consistent emotional tone and character voice adaptation.
- Voice Cloning and Custom Voices: Personalized voice creation for branding, media production, and accessibility.
- Gaming and Animation: Dynamic character dialogue with nuanced emotional expression.
- Telephony and IVR Systems: Fast, natural-sounding prompts and responses for automated phone systems.
- Accessibility Tools: Enhanced screen readers and speech aids with emotional and contextual speech understanding.
Octave 2 benchmarks by 
Artificial Analysis
Human-preference results for Octave 2 in speech arena, next to models available on AI/ML API. Data retrieved Nov 3, 2026.
AI/ML API price
USD per generation
Models on AI/ML API
Arena results for models you can call with the same API key.
Speech Arena
Listeners hear two clips of the same text and choose the more natural one. Octave 2 ranks #63 of 101.
Octave 2 API pricing
| Usage | Price | Unit |
|---|---|---|
| Speech generation | $0.078 | per generation |
Prices from the AI/ML API price list, checked on Nov 4, 2026.
Octave 2 vs other speech models: prices
AI/ML API rates for 5 models, per generation.
| Model | Per generation |
|---|---|
 Octave 2 | $0.078 |
 Inworld TTS-1-Max | $0.013 |
 Qwen3 TTS Flash | $0.013 |
 MiniMax Speech 2.6 Turbo | $0.078 |
| MiniMax Speech 2.6 HD | $0.13 |
How to use the Octave 2 API
View docs
Build with your agent
Give your agent the model details, code and documentation.
Paste it into your coding agent to build the integration.
1Get your API key
Create API keyexport AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"2Make your first request
curl 'https://api.aimlapi.com/v1/tts' \
-H "Authorization: Bearer $AIMLAPI_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "hume/octave-2",
"text": "Your order has shipped. It will arrive on Thursday between nine and eleven in the morning. Reply to this message if you need to change the delivery time."
}'import os
import requests
headers = {
"Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
"Content-Type": "application/json",
}
payload = {
"model": "hume/octave-2",
"text": "Your order has shipped. It will arrive on Thursday between nine and eleven in the morning. Reply to this message if you need to change the delivery time."
}
response = requests.post("https://api.aimlapi.com/v1/tts", headers=headers, json=payload, timeout=120)
response.raise_for_status()
print(response.json())const response = await fetch("https://api.aimlapi.com/v1/tts", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
"model": "hume/octave-2",
"text": "Your order has shipped. It will arrive on Thursday between nine and eleven in the morning. Reply to this message if you need to change the delivery time."
}),
});
if (!response.ok) throw new Error(`HTTP ${response.status}`);
console.log(await response.json());Models similar to Octave 2
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Octave 2 FAQ
What inputs and outputs does Octave 2 support?
Octave 2 takes text as input and returns audio.
When was Octave 2 released?
Octave 2 became available on January 5, 2026.
How much does Octave 2 cost?
Octave 2 is priced at $0.078 / 1M tokens.
How is Octave 2 billed?
Octave 2 is billed per generation, a fixed charge per output rather than by prompt length.
Who created Octave 2?
Octave 2 was built by Hume AI.
How do I call Octave 2 on AI/ML API?
Send a request to https://api.aimlapi.com/v1/tts with hume/octave-2 as the model id.
Is Octave 2 available through a single API key?
Yes. Octave 2 is served through AI/ML API, so the same key and endpoint format used for other models applies.
Can Octave 2 generate speech with emotional expression?
Yes, Octave 2 is designed as a text-to-speech model with emotional expression capabilities.
What is the Octave 2 model ID?
Use hume/octave-2 as the model parameter. Requests go to https://api.aimlapi.com/v1/tts with your AI/ML API key.