Common Voice Scripted Speech 25.0 - Cornish

Kernowek — Cornish (kw)

This datasheet is for cv-corpus-25.0-2026-03-09 of the Mozilla Common Voice Scripted Speech dataset for Cornish [Kernowek - kw]. The dataset contains 11264 clips representing 12.89 hours of recorded speech (12.37 hours validated) from 10 speakers, recorded from a text corpus of 9,609 sentences.

Language

Cornish, or Kernewek, is a Brythonic language, alongside Breton and Welsh, and part of the Celtic Indo-European language family. It is an indigenous language of the United Kingdom, with most speakers located in Cornwall. In the 2021 UK Census 567 people self-identified Cornish as their main language. UNESCO has classified its status as "severely endangered".

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: 3,876 of 11,264 clips (34.4%), 4 of 10 speakers (40.0%)

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: 9,950 of 11,264 clips (88.3%), 6 of 10 speakers (60.0%)

Data splits for modelling

Clip buckets

Training splits

Training split coverage: 8,624 of 10,806 validated clips (79.8%)

The dataset contains 10806 validated, 398 invalidated, and 60 unresolved clips. The average clip duration is 4.121 seconds.

Text corpus

The dataset contains 10.8 validated hours of speech from 10 unique contributors.

• Average sentence length (tokens): 6.4

• Average sentence length (characters): 31

Validated sentences: 9,609

The corpus contains 9,609 sentences: 9,609 validated and 0 unvalidated (0 pending review, 0 rejected), with 43 reported for review.

Writing system

Cornish has several writing systems in place. The majority of this dataset uses the Standard Written Form, established in 2008.

Symbol table

The dataset uses the following characters: ' - ! , . ? a b c d e f g h i j k l m n o p r s t u v w x y z

Sample

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

1. Hy daras yw gwyrdh.

2. Ty a wra mos dhe'n sodhva. Res yw dhis mos dhe'n sodhva.

3. Yma bleujen genen.

4. Yma blew berr dhedhi.

5. Yma kathes y'n lowarth. Py lies eus?

Sources

The text for this dataset comes from the following sources:

• IndyLan Cornish course. Author: Cornish Language Office. Standard Written Form.

• Individual sentences submitted by users through the Mozilla Common Voice interface (public domain)

Text domains

• General — The majority of this dataset focuses on conversational phrases with the intention to cover a broad range of grammatical points.

Recommended post-processing

• Check the data for Unicode errors in the Cornish. These should be the character '.

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

• 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

Acknowledgements

Datasheet authors

• Sam Rogerson

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