Hume Octave 2 (TTS)
Emotionally expressive TTS from Hume AI (Octave = “Omni-capable text and voice engine”).
Model idversion: 2
Price$0.15 per 1K characters
Checked29 September 2026
Where it stands
84newer speech and audio models since its release
- NVIDIA Nemotron 3.5 Transcribe (30B-A4B)28 Oct 2026
- Hy-SimulMT-30B-A3B22 Oct 2026
- Eleven Realtime v1 Max / Mini20 Oct 2026
- Voxtral Mini Transcribe 3 (+ Mini Transcribe Realtime 3)20 Oct 2026
- Voxtral Small Transcribe 320 Oct 2026
The 5 newest are listed. All speech and audio models
- Before it from Hume AI
- Hume EVI 3 / EVI 4 mini (speech-to-speech)29 May 2025
- Weights
- Closed weights; access is hosted only.
How to call it
2 ways to use Hume Octave 2 (TTS), with the model id each provider expects.
| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| Hume API | version: 2 |
https://api.hume.ai/v0/tts |
dev.hume.ai |
| Web app | platform.hume.ai |
Pricing
| Per 1K characters | $0.15 |
|---|
As published: “per 1K characters overage on Free/Starter/Creator plans; $0.12 Pro, $0.10 Scale, $0.05 Business (plans include monthly character quotas)”.
Source: hume.ai, checked 29 September 2026.
Specs
- Input
- Text and audio
- Output
- Audio
- Context window
- Not published
- Max output
- Not published
- Open weights
- No
- Licence
- Proprietary
- Released
- 1 October 2025
- Status
- Current
- Type
- Speech and audio
What stands out
What its maker marketed at launch, and what people found later, each with its source.
LLM-based emotionally intelligent TTS
Speech-language model that infers emotion and delivery from text; natural-language ‘acting instructions’ steer tone. Octave 2 at half the price of Octave 1, ~100 ms model latency (docs) / under 200 ms (launch blog).
11 languages, instant cloning from 15 s
Arabic, English, French, German, Hindi, Italian, Japanese, Korean, Portuguese, Russian, Spanish; instant voice cloning from a ~15 s recording with accent prediction across languages; voice design from a text prompt (English only).
Voice conversion and phoneme editing
Launch post describes voice conversion (swap speaker) and direct phoneme-level pronunciation editing as new capabilities for a speech-language model.
Notes
Select via version: 2 in the TTS request body (1 = Octave 1, English/Spanish, ~200 ms). Docs still label Octave 2 ‘(preview)’ as of 2026-09-29. Auth header X-Hume-Api-Key. Max 5,000 chars per utterance, 1,000-char descriptions. Formats MP3/WAV/PCM. No Octave 3 announced on Hume’s blog through Sept 2026. Speech-to-speech sibling: see hume-evi.
curl https://api.hume.ai/v0/tts -H "X-Hume-Api-Key: $HUME_API_KEY" -H "Content-Type: application/json" \
-d '{"version":2,"utterances":[{"text":"I cannot believe it worked!","description":"a delighted, breathless scientist"}]}'
Sources: https://dev.hume.ai/reference/text-to-speech-tts/synthesize-json , https://www.hume.ai/pricing , https://www.hume.ai/blog/octave-2-launch