<aside> 📢 Requirements: Professional or Enterprise plan

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Our Custom Dictionary functionality biases the speech recognition algorithms used by Amazon Transcribe and Speechmatics towards a predefined set of terms, improving transcription accuracy for content containing:

• Product names
• Technical jargon
• People’s names
• Brand-specific terminology

This is particularly useful when you know the vocabulary that's likely to appear in your video.

Custom dictionaries are language-aware rather than locale-specific, meaning a single dictionary can be reused across regional variants of the same language. For more information, see Language variants.

Creating a custom dictionary

Before using the Custom dictionary feature, you’ll need to create one:

1. Open the Custom dictionaries page from the sidebar.

2. Click New custom dictionary.

3. Give your dictionary a name, select its language and provide a description if needed.

4. Click Create & add terms.

   

5. Add your terms. We recommend keeping your dictionary to fewer than 1,000 entries.

   

   • Add terms manually: type them manually or paste them in bulk (from a text editor or spreadsheet)
   • Paste list of terms: paste the terms separated by new lines
   • Import from CSV
     • Choose or drag and drop a CSV file
     • Make sure the file’s first row contains these three column headers: term, sounds like, and note
   • Generate terms from a source: ****Use AI to extract terms from:
     • A URL
     • A document of up to 25,000 characters at a time, including PDF, Word and text files
     • An existing CaptionHub project that you select
     • Free text that you paste

6. Click Submit or Update to save the terms to your dictionary.

   

7. If you used Generate terms from a source, review the suggested terms, select the ones you'd like to add and click Add accepted terms.

   

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Note: Large custom dictionaries can reduce transcription quality, although they do not affect transcription latency. If your dictionary contains a large number of entries, CaptionHub will display a warning.

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The Sounds like field is optional and can be used when a term's spelling does not clearly indicate its pronunciation. This is particularly useful for names, product names, abbreviations or terms such as Porsche 911 or .NET.