Speech-to-text

Speech-to-text for Swiss German and 100 more languages, tailored to you

Swiss German

Every dialect region, straight into Standard German

Swiss German has no standard written form. Our model hears dialect and writes Standard German you can use right away. Trained on recordings from every dialect region: Basel, Bern, Grisons, Eastern Switzerland, Valais, Central Switzerland, Zurich.

Research partner: Institute for Data Science at the University of Applied Sciences and Arts Northwestern Switzerland (FHNW) Joint research on corpora, models and evaluation methods for Swiss German.
Example: Bernese German
Spoken «Mir hei ds Projekt letscht Wuche fertig gmacht und itz gö mer's go teste.»
Transcript Wir haben das Projekt letzte Woche fertiggestellt und jetzt gehen wir es testen.
Benchmark

On par with the state of the art

On the STT4SG-350 test set (35 hours of audio from every Swiss German dialect region), our current model reaches a word error rate of 12.4 (0 = identical to the reference, 100 = every word is wrong). This puts it on par with the current state of the art (Timmel et al.), ahead of the model in the STT4SG-350 paper and far ahead of the original Whisper model.

Word Error Rate lower = better
Timmel et al. (2024)12.1
Ateleris model12.4
STT4SG-350 paper (2023)14.0
Whisper large-v322.8

Performance of our current model per dialect region on the STT4SG-350 test set:

Word Error Rate lower = better
Basel12.4
Bern13.6
Grisons11.7
Eastern Switzerland13.0
Valais12.0
Central Switzerland10.8
Zurich13.4

Whisper large-v3 and Ateleris model: our own measurement
STT4SG-350 paper (2023): Plüss et al. (2023)
Timmel et al. (2024): Timmel et al. (2024)

Other languages

Transcribe 100 different languages

Besides Swiss German, we cover German, French, Italian, English, Spanish and many other languages from around the world – with automatic language detection.

Full list of supported languages: Languages

Please note: the transcription quality is not the same for all 100 languages. For some, there simply isn't enough training data to reach good quality. We're happy to help with specific questions, e.g. about quality for less common languages.

Performance of our model across languages on the FLEURS dataset:

Word Error Rate lower = better
German4.9
English4.1
French5.3
Italian3.0
Spanish2.8
Custom models

Optimal transcription quality with custom models

If you have your own data, meaning audio and the matching transcripts, we can train a model on it that performs significantly better than any standard model. The custom model runs through the same API or on your own infrastructure.

Case study: council minutes, Solothurn dialect, 60 h of training data Word Error Rate (lower = better)
51.5
44.4
36.8
Whisper large-v3Standard model
Ateleris beforeOur base model
Ateleris afterCustom model

The word error rates are higher than on STT4SG-350 because they are measured against final minutes, which are heavily edited rather than a word-for-word record. So no model can get anywhere near 0 %.

Rare dialect or low-resource language?

Whatever the language: if you have transcribed recordings, we can train a model on them. Even 10 hours of data often bring a clear improvement.

Special requirements for the transcript?

Clean read instead of verbatim, your own formatting rules, domain vocabulary: with example data in your target format, the model learns exactly that style.

Process
1Analysis
2Training
3Evaluation
4Operation
Outlook

What we're working on

The service keeps getting better. New model versions ship through the same API, with no changes to your integration.

End of 2026 In progress Domain vocabulary

Pass your own terms and names via the API.

Q1 2027 In progress Better transcription quality

Improved quality for low-quality recordings and audio with background noise.

2027 Planned LLM post-processing

Pass context about the recording and instructions via the API; an LLM then improves or rewrites the transcript as instructed.