Overview
Hume AI is a research-driven voice platform built on the science of emotional expression. Its flagship product, the Empathic Voice Interface (EVI), is a real-time speech-to-speech agent that listens to more than the words you say - it measures prosody, vocal bursts, and tone across dozens of emotional dimensions, then shapes its reply accordingly. If a caller sounds frustrated, EVI softens; if they interrupt, it stops, listens, and acknowledges. The second product, Octave, is an expressive text-to-speech engine where you can direct emotional delivery with plain-language prompts like ‘warm and reassuring’ or ‘anxious and apologetic’. Everything ships as REST and WebSocket APIs with sub-second latency and SDKs for TypeScript, Python, and React, aimed at developers building support agents, mental-health companions, accessibility tools, and game characters. SOC 2 Type II and HIPAA-aligned terms make it viable for regulated industries.
Key Features
- EVI empathic voice interface with real-time emotion detection and sub-600ms responses
- Octave TTS with steerable emotional delivery via natural-language voice prompts
- Expression Measurement API analyzing voice, face, and text across 50+ emotional dimensions
- Free voice cloning on all plans with no per-clone fees
- WebSocket streaming APIs with TypeScript, Python, and React SDKs
- SOC 2 Type II, GDPR, and HIPAA-aligned compliance on Pro tiers and above
Pricing
| Plan | Price | For |
|---|---|---|
| Free | $0 | 10K TTS characters + 5 EVI minutes to prototype |
| Starter | $3/mo | Hobby projects, 30K characters + 40 EVI minutes |
| Creator | $14/mo | Serious prototypes, 140K characters + 200 EVI minutes |
| Pro | $70/mo | Production apps, 1M characters + 1,200 EVI minutes |
| Scale / Business | $200-$500/mo | High-volume deployments with cheaper overage |
| Enterprise | Custom | Unlimited usage, Slack support, custom concurrency |
Comparison
Compared to ElevenLabs, Hume trades some raw narration polish for emotional range - blind listeners identify Octave’s intended emotion far more reliably, while ElevenLabs stays cleaner on neutral long-form audio. Compared to Play.ht, Hume is more developer-centric with its conversational EVI stack rather than a content-creation studio. And against Resemble AI, which leans into enterprise voice cloning and deepfake detection, Hume’s edge is the real-time empathic conversation layer no one else ships.
Hands-on Verdict
Hume AI is the platform I use to measure and express emotion in voice and text — its models read tone and generate more empathetic speech. It’s more emotion-aware than a standard ElevenLabs voice and a different layer than a chatbot. For plain TTS I use ElevenLabs.
Who it’s for: developers building expressive UX. Tip: use the expression measurement on caller or support audio — Hume’s signal is emotional nuance, so feed it natural speech, not scripted reads.