Pronunciation dictionaries

Learn how to control how your AI agent pronounces specific words and phrases.

Overview

Pronunciation dictionaries allow you to customize how your AI agent pronounces specific words or phrases. This is particularly useful for:

  • Correcting pronunciation of names, places, or technical terms
  • Ensuring consistent pronunciation across conversations
  • Customizing regional pronunciation variations
Pronunciation dictionary settings under the Voice tab

Configuration

You can find the pronunciation dictionary settings under the Voice tab in your agent’s configuration.

The phoneme function of pronunciation dictionaries only works with the Turbo v2 model, while the alias function works with all models.

Dictionary file format

Pronunciation dictionaries use XML-based .pls files. Here’s an example structure:

1<?xml version="1.0" encoding="UTF-8"?>
2<lexicon version="1.0"
3      xmlns="http://www.w3.org/2005/01/pronunciation-lexicon"
4      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
5      xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon
6        http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd"
7      alphabet="ipa" xml:lang="en-GB">
8  <lexeme>
9    <grapheme>Apple</grapheme>
10    <phoneme>ˈæpl̩</phoneme>
11  </lexeme>
12  <lexeme>
13    <grapheme>UN</grapheme>
14    <alias>United Nations</alias>
15  </lexeme>
16</lexicon>

Supported formats

We support two types of pronunciation notation:

  1. IPA (International Phonetic Alphabet)

    • More precise control over pronunciation
    • Requires knowledge of IPA symbols
    • Example: “nginx” as /ˈɛndʒɪnˈɛks/

  2. CMU (Carnegie Mellon University) Dictionary format

    • Simpler ASCII-based format
    • More accessible for English pronunciations
    • Example: “tomato” as “T AH M EY T OW”

You can use AI tools like Claude or ChatGPT to help generate IPA or CMU notations for specific words.

Best practices

  1. Case sensitivity: Create separate entries for capitalized and lowercase versions of words if needed
  2. Testing: Always test pronunciations with your chosen voice and model
  3. Maintenance: Keep your dictionary organized and documented
  4. Scope: Focus on words that are frequently mispronounced or critical to your use case

FAQ

Currently, only the Turbo v2 model supports phoneme-based pronunciation. Other models will silently skip phoneme entries.

Yes, you can upload multiple dictionary files to handle different sets of pronunciations.

The model will use its default pronunciation rules for any words not specified in the dictionary.

Additional resources

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