Common Voice Scripted Speech 25.0 - Breton

Brezhoneg — Breton (br)

This datasheet is for cv-corpus-25.0-2026-03-09 of the Mozilla Common Voice Scripted Speech dataset for Breton [Brezhoneg - br]. The dataset contains 36377 clips representing 32.89 hours of recorded speech (30.69 hours validated) from 283 speakers, recorded from a text corpus of 41,770 sentences.

Language

Breton (Brezhoneg) is the only Celtic language spoken on the continent. It belongs to the Brittonic branch of the Celtic languages, like Welsh and Cornish. Breton is classified as "severely endangered" by the UNESCO Atlas of the World's Languages in Danger. The language declined from more than one million speakers around 1950 to less than 200 000 in 2024. After a period of intense protest that began in the 1960s, Breton gradually regained a place in schools, on road signs, then in the media, public life in general, and more recently in digital technology. With the creation of the first bilingual schools at the end of the 1970s, young people were once again speaking Breton, and a change in the way people viewed the language and its use began. Approximately 20 000 pupils attend Breton bilingual classes, either in the Diwan network (immersive teaching) or in bilingual classes in public and catholic school systems. In addition to evening breton classes for adults (~4 000), long-term courses (6 to 9 months) are offered to adults, with approximately 350 places available annually and online courses too (more than 15 000 learners).

Accents

Demographic information

The dataset includes the following self-declared age and gender distributions. A coverage summary is shown below each table.

Gender

Self-declared gender information. The table shows clip and speaker counts with percentages. Speakers who did not declare a gender are listed as Unspecified. A dash (-) indicates zero.

Gender declared: 23,477 of 36,377 clips (64.5%), 67 of 283 speakers (23.7%)

Age

Self-declared age information. The table shows clip and speaker counts with percentages. Speakers who did not declare an age are listed as Unspecified. A dash (-) indicates zero.

Age declared: 26,875 of 36,377 clips (73.9%), 91 of 283 speakers (32.2%)

Data splits for modelling

Clip buckets

Training splits

Training split coverage: 11,409 of 33,940 validated clips (33.6%)

The dataset contains 33940 validated, 2406 invalidated, and 31 unresolved clips. The average clip duration is 3.256 seconds.

Text corpus

Validated sentences: 23,286

The corpus contains 41,770 sentences: 23,286 validated and 18,484 unvalidated (18,401 pending review, 83 rejected), with 303 reported for review.

Writing system

The writing system in this dataset uses general Latin script. The diacritics à, è and é may appear in the transcription of Gwenedeg variant.

Symbol table

a â b ch c'h d e ê f g h i j k l m n ñ o ô p r s t u ù û ü v w y z

à è é (for gwenedeg variant)

c q x (foreign, loanwords)

Sample

There follows a randomly selected sample of five sentences from the corpus.

1. Hanternoz eo.

2. Buhez a zo ennañ.

3. Merzhet en deus e oa toull e chakot.

4. Penaos oc'h kroget ha perak ?

5. Tu bennak e tleo bezañ.

Sources

Text domains

Fields

Clips

Each row of a tsv file represents a single audio clip, and contains the following information:

• client_id - hashed UUID of a given user

• path - relative path of the audio file

• text - supposed transcription of the audio

• up_votes - number of people who said audio matches the text

• down_votes - number of people who said audio does not match text

• age - age of the speaker1

• gender - gender of the speaker1

• accents - accents of the speaker1

• variant - variant of the language1

• segment - if sentence belongs to a custom dataset segment, it will be listed here

• prompt_upvotes - number of upvotes the sentence prompt received

• prompt_reports - number of reports the sentence prompt received

• is_edited - whether the clip's transcription has been edited

validated_sentences.tsv

The validated_sentences.tsv file contains one row per validated sentence in the text corpus:

• sentence_id - unique identifier for the sentence

• sentence - the sentence text

• variant - the variant of the language

• sentence_domain - the domain(s) the sentence belongs to

• source - the source the sentence was collected from

• is_used - whether the sentence is still in circulation for recording

• clips_count - number of clips recorded for this sentence

unvalidated_sentences.tsv

The unvalidated_sentences.tsv file contains one row per unvalidated sentence in the text corpus:

• sentence_id - unique identifier for the sentence

• sentence - the sentence text

• variant - the variant of the language

• sentence_domain - the domain(s) the sentence belongs to

• source - the source the sentence was collected from

• up_votes - number of upvotes the sentence received

• down_votes - number of downvotes the sentence received

• status - current status of the sentence (pending or rejected)

Get involved

Community links

• Original language request on GitHub

• Ofis Publik ar Brezhoneg (public institution in charge of promoting and developing the teaching and use of the Breton language in everyday life)

• Porched niverel ar brezhoneg (portal gathering various digital tools relating to the Breton language)

• Common Voice translators on Pontoon

• Common Voice Communities

Discussions

• Common Voice on Matrix

• Common Voice on Discourse

• Common Voice on Discord

• Common Voice on Telegram

Contribute

• Speak

• Write

• Listen

• Review

Licence

This dataset is released under the Creative Commons Zero (CC-0) licence. By downloading this data you agree to not determine the identity of speakers in the dataset.

Footnotes

1. For a full list of age, gender, and accent options, see the demographics spec. These will only be reported if the speaker opted in to provide that information. ↩ ↩2 ↩3 ↩4