> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cartesia.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Custom Pronunciations

> Specify custom pronunciations for words that are hard to get right, like proper nouns or domain-specific terms.

Pronunciation dictionaries let you specify how to pronounce specific words and phrases. Try out the pronunciation tool on our [demo](https://play.cartesia.ai/demos/pronunciation) page.

A dictionary is a simple search and replace, which directs the model to use another string in lieu of the text from the transcript. The pronunciation can be either an [IPA pronunciation](/build-with-cartesia/capability-guides/phonemes) or a "sounds-like" guidance:

```json lines theme={null}
[
  {
    "text": "bayou",
    "pronunciation": "<<ˈ|b|ɑ|ˈ|j|u>>"
  },
  {
    "text": "jambalaya",
    "pronunciation": "<<ˈ|dʒ|ə|m|ˈ|b|ə|ˈ|l|aɪ|ˈ|ə>>"
  },
  {
    "text": "tchoupitoulas",
    "pronunciation": "chop-uh-TOO-liss"
  }
]
```

Save these JSONs as pronunciation dictionaries [through our API](/api-reference/pronunciation-dicts/create) or through our [playground](https://play.cartesia.ai/pronunciation):

<img src="https://mintcdn.com/cartesia-2650f86a/e1mnuMNt5eyESNEd/images/image.png?fit=max&auto=format&n=e1mnuMNt5eyESNEd&q=85&s=e5284d8275a53cb69e1fef0f32ccca4c" alt="image.png" width="1264" height="414" data-path="images/image.png" />

Once a dictionary is created, use it in any TTS API by passing its id as `pronunciation_dict_id`.

With the dictionary above, the string `I ate some jambalaya on tchoupitoulas street` becomes `I ate some <<ˈ|dʒ|ə|m|ˈ|b|ə|ˈ|l|aɪ|ˈ|ə>> on chop-uh-TOO-liss street` before being handed off to the model.

## Case Sensitivity

Dictionary matching is **case-sensitive**, with one exception: a lowercase entry also matches its sentence-start capitalized form. For example, `cat` matches both `cat` and `Cat`, but not `CAT`. An entry for `CAT` only matches `CAT`.

This applies to multi-word entries too. An entry for `green valley` matches `green valley` and `Green valley`, but not `Green Valley`.

**Use lowercase entries for common words.** These match the word both mid-sentence (`cat`) and at the start of a sentence (`Cat`), covering the two most common positions.

**Use exact capitalization for proper nouns.** A term like `LaTeX` should be entered as `LaTeX` so it doesn't collide with a different pronunciation for the common word `latex`. For multi-word proper nouns, enter the exact casing as it appears in your transcripts — for example, `Green Valley` if the transcript capitalizes both words.