Pronunciation control

Check dictionary coverage, specify custom pronunciations, and request dictionary additions to control exactly how Rime speaks your words.

Pronunciation control makes sure brand names, product names, and domain-specific words sound right before they reach your users.

There are three ways to control pronunciation:

1. Check dictionary coverage to see whether a word is already pronounced correctly out of the box.
2. Specify a custom pronunciation inline using the Rime phonetic alphabet.
3. Request a dictionary addition from the Rime team.

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Check dictionary coverage

Use the Coverage API to find words that are not yet in Rime’s pronunciation dictionary. The model still predicts a pronunciation for uncovered words, often correctly when the spelling follows common patterns. Verify uncommon words before they reach end users.

Specify a custom pronunciation inline

phonemizeBetweenBrackets works on Mist v1 and Mist v2 only. It is not supported on Mist v3 or Coda.

For Mist v1 and Mist v2, add inline phonetic strings with the Rime phonetic alphabet. Write the string by hand or generate one from a recording with the Phonemize API.

See Custom pronunciation for the full reference.

Generate the phonetic string from audio

Record the word (or synthesize it) and post the raw audio to the Phonemize API.

curl -X POST https://optimize.rime.ai/phonemize \
     -H "Authorization: Bearer $RIME_API_KEY" \
     -H "Content-Type: audio/wav" \
     --data-binary @speech.wav

The response contains the phonetic transcription of the audio:

{
  "audioId": "9b2d8ad2-0618-4e96-b255-98b2f7488061",
  "phonemeString": "h0El1o !",
  "authed": 1
}

Drop any trailing punctuation token, then paste the string into your TTS request inside curly brackets with phonemizeBetweenBrackets: true. For example: {h0El1o}.

For brand or product names on Mist v3 or Coda, request a dictionary addition or respell the word in plain English. Respelling is approximate.

Request a dictionary addition

If a word is mispronounced and you’d like it fixed at the dictionary level, reach out to your account manager via Slack or email, or contact [e-mail]. Rime’s linguists typically review and add new words within one week.

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What to check first

• Brand names, technical terms, and made-up words are the most common sources of mispronunciation; verify these first.
• Re-check coverage whenever you add new or domain-specific content.
• For flows where pronunciation control matters most, use Mist v1/v2 so you can correct pronunciations inline.