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Speech to TextFeatures

Formatting and punctuation

Three features shape how the transcript text is written: the output locale standardizes regional spelling, smart formatting converts spoken values into their written form, and punctuation controls which marks appear.

Availability​

Output locale, smart formatting, and punctuation and casing are available for every interaction pattern and every model. See Feature availability.

Output locale​

Some languages have multiple spelling conventions that vary by region. To ensure consistent spelling throughout your transcript, specify an output locale:

{
  "type": "transcription",
  "transcription_config": {
    "model": "enhanced",
    "language": "en",
    "output_locale": "en-GB"
  }
}

Available English locales:

  • British English (en-GB)
  • US English (en-US)
  • Australian English (en-AU)

Available Mandarin locales:

  • Simplified Mandarin (cmn-Hans, default)
  • Traditional Mandarin (cmn-Hant)

Recommended for English transcription. Without a specified locale, spelling may be inconsistent within the same transcript.

Smart formatting​

Smart formatting converts spoken numbers, dates, currencies, and other entities into properly formatted text. This makes transcripts more readable without losing timing information.

An entity is a spoken value that has a conventional written form, such as a number, date, currency, time, or measurement. Speechmatics detects each entity and converts it from the words as spoken into its written form. For example, the spoken words "nineteen ninety nine" become "1999" in the output.

Smart formatting is applied by default. To also expose the structure of each entity in the JSON output — its class, and the individual spoken and written words it is made from — see Entity detection.

Languages for smart formatting​

Each language follows its own conventions for thousand separators, decimal separators, and currency symbol position. For example:

  • English: commas for thousands (20,000), decimal points (10.5), currency symbols before values ($10)
  • German: periods for thousands (20.000), commas for decimals (10,5), currency symbols after values with a non-breaking space (10 $)
  • French: non-breaking spaces for thousands (20 000), commas for decimals (10,5), currency symbols after values with a non-breaking space (10 $)

Smart formatting has had dedicated work for consistent results in these languages:

  • Cantonese
  • Dutch
  • English
  • French
  • German
  • Hindi
  • Italian
  • Japanese
  • Mandarin (Simplified and Traditional)
  • Mandarin & English (bilingual)
  • Mandarin Malay Tamil & English (multilingual)
  • Norwegian
  • Portuguese
  • Russian
  • Spanish
  • Swedish
  • Tamil & English (bilingual)

Other languages still format numbers and entities on a best-effort basis through the model, with variable results. If you rely on formatting for a language that is not listed, test it with representative audio rather than assuming full coverage.

Formatting coverage is not reported by feature discovery, which covers transcription, translation, and language identification. This page is the reference for formatting language support.

Punctuation​

All Speechmatics language packs support punctuation to improve transcript readability. Each language supports specific punctuation marks:

LanguageSupported marksEnd-of-sentence marksNotes
Cantonese, Mandarin， 。 ？ ！ 、。 ？ ！Full-width punctuation
Japanese。 、。Full-width punctuation
Hindi। ? , !। ? !
All other languages. , ! ?. ! ?

Configure punctuation marks​

Control which punctuation marks appear in your transcripts using the punctuation_overrides setting:

"transcription_config": {
   "model": "enhanced",
   "language": "en",
   "punctuation_overrides": {
      "permitted_marks": [".", ","],
      "sensitivity": 0.4
   }
}

This configuration allows only periods and commas, with no question or exclamation marks, and sets punctuation sensitivity to 0.4, lower than the default 0.5.

To select all marks, set "permitted_marks": ["all"]. If you use an empty list, no punctuation marks appear in the output.

The sensitivity parameter accepts values from 0 to 1. Higher values produce more punctuation in the output.

Disabling punctuation may slightly reduce speaker diarization accuracy. See speaker diarization for details.

Next steps​