Ursa

Ursa was released in March 2023 with new Standard and Enhanced English models. Both live and recorded transcription used the same underlying recognition models.

Access not confirmed

Audio representations, phonemes and words

Ursa first learned audio representations from more than a million hours of unlabelled speech across 50 languages. A supervised acoustic model then mapped those representations to phoneme probabilities. A language model converted the probabilities into likely words.Speechmatics: Introducing Ursa, 7 March 2023

Its domain study compared performance across medical, financial, technical, political and construction recordings. The study addressed generalization without custom domain adaptation, rather than presenting those domains as five separately released models.Speechmatics: Ursa and domain generalization

Practical guidance. The two-billion-parameter figure applies to the self-supervised component. Treating it as an end-to-end system size would omit the acoustic and language components.Speechmatics: Introducing Ursa, 7 March 2023

Specifications & access

Ursa specifications
DetailValue and conditions
StatusAccess not confirmed
Launch date
Model identifiersUrsa StandardUrsa Enhanced
Enhanced speech representation modelAbout two billion parameters; this is not a total for the whole pipelineSpeechmatics: Introducing Ursa, 7 March 2023
Exact checkpoint accessNo current frozen Ursa checkpoint verifiedSpeechmatics documentation: Models

Related models

  • Historical recognition generation that expanded self-supervised training and language coverage.

    Launch date Access not confirmed
  • Bilingual recognition model that transcribes Spanish and English in one stream.

    Launch date API · Provider product
  • General speech recognition model that prioritizes accuracy across supported language packs.

    Launch date not confirmedAPI · Provider product
  • General speech recognition model that prioritizes transcription throughput.

    Launch date not confirmedAPI · Provider product