Hume Octave overage $0.05 to $0.15 per 1,000 characters vs Sume TTS

Hume AI's overage price for Octave text-to-speech falls from $0.15 per 1,000 characters on the Free plan to $0.05 on Business, and its EVI voice conversation product runs from $0.07 a minute on Starter and Creator ($0.06 on Free) down to $0.04 on Business. Sume's text-to-speech is $0.0475 per 1,000 characters on every account, so it sits below Hume's overage on every plan, though only by $0.0025 against Business's $0.05.

Prices are from the Hume pricing page, read 2026-10-03. Hume's plan fees and included allowances matter more than overage if you stay inside them.

Hume's plans

The page lists seven tiers, from Free to Enterprise, with monthly fees and included allowances for both products.

Reading the Octave numbers

The page says the Free plan includes 10,000 characters a month, about 10 minutes of speech, and unlimited on Enterprise. A script of 30,000 characters on Free is 10,000 included plus 20,000 at $0.15 per thousand, $3.00. On Sume, 30,000 characters is $1.425 at $0.0475 per 1,000, sent as two requests under the 20,000-character cap.

The gap narrows as you move up Hume's tiers. At the Business overage of $0.05, the same 30,000 characters would be $1.50, about 7.5 cents above Sume. That is only a rate comparison: Business costs $500 a month and includes 10,000,000 characters.

A 100,000-character month

Suppose a team narrates 100,000 characters in a month. On Hume Free, 10,000 are included and 90,000 are billed at $0.15 per 1,000, which is $13.50. On Sume the same 100,000 characters cost $4.75, sent as requests of up to 20,000 characters. These figures are overage only and ignore plan fees and the larger allowances on paid tiers, so a Hume subscriber inside their allowance pays less per character than either number.

What Sume does and does not do

Sume text to speech is $0.0475 per 1,000 characters, up to 20,000 characters per request. Speech to text is $0.01 per minute of audio, up to 600 seconds per job.

Sume does not run a conversational speech-to-speech service like EVI. Its voice output is a rendered file from a text script.

Per-minute speech figures assume 750 to 800 characters a minute, the range Cartesia publishes as credits per minute of audio, at one credit per character; a script's real length varies with pace.

• Good fit: scripted narration, voiceovers and avatar speech, priced per character with no tiers.
• Poor fit: a live emotional voice chat; that needs EVI or a similar product.
• Compare the stack cost of live conversation in the voice agent cost breakdown.