Expression Measurement API
The Expression Measurement API measures emotional and vocal expression in speech, marketed as 'Measure expression in voice, offline or in real time.' Hume describes two endpoints on the one page: 'The Tagger API returns 600+ expression and voice dimensions from any audio, at scale. The Prosody API delivers real-time emotional expressions during live conversations.' Measured dimensions include emotion categories, speaking styles, vocal qualities such as pace, warmth and hesitation, and expression intensity with confidence scores.
Find alternatives to Expression Measurement API
No public price. Bought on its own through Hume's sales team - the page has no self-serve signup and its only CTA is 'Contact Research'. It is not on Hume's self-serve pricing rate card, which covers only Octave text-to-speech and EVI speech-to-speech; it appears there only as a footer Platform link. pricing_url deliberately omitted for that reason.
What it does
- Data analysis
- Evaluation and observability
Sources
- Pricing
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No pricing shown; the only call to action is 'Contact Research'.
- Description
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Official documentation · 5 Sep 2026
Headline 'Measure expression in voice, offline or in real time'; 'The Tagger API returns 600+ expression and voice dimensions from any audio, at scale. The Prosody API delivers real-time emotional expressions during live conversations.'
- What it does
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Official documentation · 5 Sep 2026
Voice/audio modality only as of this fetch - no mention of facial, image, video or text modalities on the current page, which is a change worth noting against older public descriptions of this API.
- Sold within
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Live re-check 2026-09-15: hume.ai/expression-measurement-api carries no pricing or bundling language at all, only a "Contact Research" CTA — does not state standalone status either way.
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