---
datasets:
- CoRal-project/coral-v2
language:
- da
base_model:
- facebook/wav2vec2-xls-r-300m
metrics:
- wer
- cer
license: openrail
pipeline_tag: automatic-speech-recognition
model-index:
- name: roest-wav2vec2-315m-v2
results:
- task:
type: automatic-speech-recognition
name: Automatic Speech Recognition
dataset:
name: CoRal read-aloud
type: alexandrainst/coral
split: test
args: read_aloud
metrics:
- type: cer
value: 6.5% ± 0.2%
name: CER
- type: wer
value: 16.3% ± 0.4%
name: WER
---
# Pre-release of Roest-wav2vec2-315m-v2
This is a pre-release of a Danish state-of-the-art speech recognition model, trained as part of the CoRal project by [Alvenir](https://www.alvenir.ai/).
This repository contains a Wav2Vec2 model trained on the [CoRal-v2 dataset](https://huggingface.co/datasets/CoRal-project/coral-v2/tree/main). The CoRal-v2 dataset includes a rich variety of Danish conversational and read-aloud data, distributed across diverse age groups, genders, and dialects. The model is designed for automatic speech recognition (ASR).
## Quick Start
Start by installing the required libraries:
```shell
$ pip install transformers kenlm pyctcdecode
```
Next you can use the model using the `transformers` Python package as follows:
```python
>>> from transformers import pipeline
>>> audio = get_audio() # 16kHz raw audio array
>>> transcriber = pipeline(model="CoRal-project/roest-wav2vec2-315m-v2")
>>> transcriber(audio)
{'text': 'your transcription'}
```
---
## Transcription Examples
Explore the following audio samples along with their transcriptions and accuracy metrics. Each example showcases the model's performance with different Danish dialects.
### Example 1 - Vestjysk Dialect
**Audio Sample:**
**Model Transcription:**
*det blev til yderlig ti mål i den første sæson på trods af en position som back*
**Target Transcription:**
*det blev til yderligere ti mål i den første sæson på trods af en position som back*
- **Character Error Rate (CER):** 3.7%
- **Word Error Rate (WER):** 5.9%
---
### Example 2 - Sønderjysk Dialect
**Audio Sample:**
**Model Transcription:**
*en arkitektoniske udformning af pladser forslagene iver benzen*
**Target Transcription:**
*den arkitektoniske udformning af pladsen er forestået af ivar bentsen*
- **Character Error Rate (CER):** 20.3%
- **Word Error Rate (WER):** 60.0%
---
### Example 3 - Nordsjællandsk Dialect
**Audio Sample:**
**Model Transcription:**
*østrig og ungarn samarbejder om søen gennem den østrigske og ungarske vandkommission*
**Target Transcription:**
*østrig og ungarn samarbejder om søen gennem den østrigske og ungarske vandkommission*
- **Character Error Rate (CER):** 0.0%
- **Word Error Rate (WER):** 0.0%
---
### Example 4 - Lollandsk Dialect
**Audio Sample:**
**Model Transcription:**
*det er produceret af thomas helme og indspillede i easy sound recording studio i københavn*
**Target Transcription:**
*det er produceret af thomas helmig og indspillet i easy sound recording studio i københavn*
- **Character Error Rate (CER):** 4.4%
- **Word Error Rate (WER):** 13.3%
---
## Model Details
Wav2Vec2 is a state-of-the-art model architecture for speech recognition, leveraging self-supervised learning from raw audio data. The pre-trained [Wav2Vec2-XLS-R-300M](facebook/wav2vec2-xls-r-300m) has been fine-tuned for automatic speech recognition with the [CoRal-v2 dataset](https://huggingface.co/datasets/CoRal-project/coral-v2/tree/main) dataset to enhance its performance in recognizing Danish speech with consideration to different dialects. The model was trained for 30K steps using the training setup in the [CoRaL repository](https://github.com/alexandrainst/coral/tree) by running:
```
python src/scripts/finetune_asr_model.py model=wav2vec2-small max_steps=30000 datasets.coral_conversation_internal.id=CoRal-project/coral-v2 datasets.coral_readaloud_internal.id=CoRal-project/coral-v2
```
The model is evaluated using a Language Model (LM) as post-processing. The utilized LM is the one trained and used by [CoRal-project/roest-wav2vec2-315m-v1](https://huggingface.co/CoRal-project/roest-wav2vec2-315m-v2).
---
## Dataset
### [CoRal-v2](https://huggingface.co/datasets/CoRal-project/coral-v2/tree/main)
- **Subsets**:
- Conversation
- Read-aloud
- **Language**: Danish.
- **Variation**: Includes various dialects, age groups, and gender distinctions.
### License
Note that the dataset used is licensed under a custom license, adapted from OpenRAIL-M, which allows commercial use with a few restrictions (speech synthesis and biometric identification). See [license](https://huggingface.co/Alvenir/coral-1-whisper-large/blob/main/LICENSE).
---
## Evaluation
The model was evaluated using the following metrics:
- **Word Error Rate (WER)**: The percentage of words incorrectly transcribed.
- **Character Error Rate (CER)**: The percentage of characters incorrectly transcribed.
**OBS!** It should be noted that the [CoRal test dataset](https://huggingface.co/datasets/alexandrainst/coral/viewer/read_aloud/test) does not contain any conversation data, whereas the model is trained for read-aloud and conversation, but is only tested on read-aloud in the [CoRal test dataset](https://huggingface.co/datasets/CoRal-project/coral/viewer/read_aloud/test).
| Model | Number of parameters | Finetuned on data of type | [CoRal](https://huggingface.co/datasets/alexandrainst/coral/viewer/read_aloud/test) CER | [CoRal](https://huggingface.co/datasets/alexandrainst/coral/viewer/read_aloud/test) WER |
| :----------------------------------------------------------------------------------------------- | -------------------: | --------------------------: | --------------------------------------------------------------------------------------: | --------------------------------------------------------------------------------------: |
| [CoRal-project/roest-wav2vec2-315M-v2](https://huggingface.co/CoRal-project/roest-wav2vec2-315m-v2) | 315M | Read-aloud and conversation | 6.5% ± 0.2% | 16.3% ± 0.4% |
| [CoRal-project/roest-whisper-large-v1](https://huggingface.co/CoRal-project/roest-whisper-large) | 1540M | Read-aloud | **4.3% ± 0.2%** | **10.4% ± 0.3%** |
| [CoRal-project/roest-wav2vec2-315M-v1](https://huggingface.co/CoRal-project/roest-wav2vec2-315m-v1) | 315M | Read-aloud | 6.6% ± 0.2% | 17.0% ± 0.4% |
| [mhenrichsen/hviske-v2](https://huggingface.co/syvai/hviske-v2) | 1540M | Read-aloud | 4.7% ± 0.2% | 11.8% ± 0.3% |
| [openai/whisper-large-v3](https://hf.co/openai/whisper-large-v3) | 1540M | - | 11.4% ± 0.3% | 28.3% ± 0.6% |
**OBS!** Benchmark for hviske-v2 has been reevaluted and the confidence interval is larger than reported in the model card.
### Detailed evaluation across demographics on the CoRal test data
### Table WER scores in % of evaluation across demographics on the CoRal test data
| Category | roest-whisper-large-v1 | roest-wav2vec2-315m-v1 | roest-wav2vec2-315m-v2 |
|:---:|:---:|:---:|:---:|
| female | 11.5 | 18.5 | 17.7 |
| male | 9.4 | 15.5 | 14.9 |
| 0-25 | 9.0 | 14.7 | 14.0 |
| 25-50 | 10.1 | 16.6 | 15.8 |
| 50+ | 11.3 | 18.2 | 17.7 |
| Bornholmsk | 9.8 | 17.7 | 15.7 |
| Fynsk | 12.1 | 18.3 | 17.7 |
| Københavnsk | 5.9 | 10.2 | 10.0 |
| Non-native | 12.2 | 20.9 | 19.4 |
| Nordjysk | 4.5 | 7.7 | 7.5 |
| Sjællandsk | 7.6 | 12.6 | 12.7 |
| Sydømål | 10.0 | 14.9 | 15.3 |
| Sønderjysk | 17.5 | 26.0 | 25.4 |
| Vestjysk | 15.0 | 26.3 | 25.2 |
| Østjysk | 7.5 | 11.7 | 11.3 |
| Overall | 10.4 | 17.0 | 16.3 |
### Table CER scores in % of evaluation across demographics on the CoRal test data
| Category | roest-whisper-large-v1 | roest-wav2vec2-315m-v1 | roest-wav2vec2-315m-v2 |
|:---:|:---:|:---:|:---:|
| female | 5.1 | 7.4 | 7.2 |
| male | 3.6 | 5.8 | 5.7 |
| 0-25 | 3.4 | 5.4 | 5.3 |
| 25-50 | 4.0 | 6.2 | 6.0 |
| 50+ | 5.0 | 7.5 | 7.4 |
| Bornholmsk | 3.8 | 6.8 | 6.1 |
| Fynsk | 5.1 | 7.4 | 7.2 |
| Københavnsk | 1.9 | 3.3 | 3.2 |
| Non-native | 4.8 | 7.8 | 7.5 |
| Nordjysk | 1.6 | 2.6 | 2.8 |
| Sjællandsk | 3.0 | 4.4 | 4.5 |
| Sydømål | 4.1 | 6.4 | 6.4 |
| Sønderjysk | 8.8 | 11.9 | 11.6 |
| Vestjysk | 6.4 | 10.1 | 9.8 |
| Østjysk | 2.6 | 4.0 | 4.1 |
| Overall | 4.3 | 6.6 | 6.5 |
### Roest-wav2vec2-315M with and without language model
The inclusion of a post-processing language model can affect the performance significantly. The Roest-v1 and Roest-v2 models are using the same Language Model (LM). The utilized LM is the one trained and used by [alexandrainst/roest-wav2vec2-315m-v1](https://huggingface.co/alexandrainst/roest-315m).
| Model | Number of parameters | Finetuned on data of type | Postprocessed with Language Model | [CoRal](https://huggingface.co/datasets/alexandrainst/coral/viewer/read_aloud/test) CER | [CoRal](https://huggingface.co/datasets/alexandrainst/coral/viewer/read_aloud/test) WER |
| :-------------------------------------------------------------------------------------------- | -------------------: | --------------------------: | --------------------------------: | --------------------------------------------------------------------------------------: | --------------------------------------------------------------------------------------: |
| [CoRal-project/roest-wav2vec2-315M-v2](https://huggingface.co/CoRal-project/roest-wav2vec2-315m-v2) | 315M | Read-aloud and conversation | Yes | **6.5% ± 0.2%** | **16.3% ± 0.4%** |
| [CoRal-project/roest-wav2vec2-315M-v2](https://huggingface.co/CoRal-project/roest-wav2vec2-315m-v2) | 315M | Read-aloud and conversation | No | 8.2% ± 0.2% | 25.1% ± 0.4% |
| [alexandrainst/roest-wav2vec2-315m-v1](https://huggingface.co/CoRal-project/roest-wav2vec2-315m-v1) | 315M | Read-aloud | Yes | 6.6% ± 0.2% | 17.0% ± 0.4% |
| [alexandrainst/roest-wav2vec2-315m-v1](https://huggingface.co/CoRal-project/roest-wav2vec2-315m-v1) | 315M | Read-aloud | No | 8.6% ± 0.2% | 26.3% ± 0.5% |
### Detailed Roest-wav2vec2-315M with and without language model on different dialects
Here are the results of the model on different danish dialects in the test set:
| | Roest-v1 | | Roest-v1 | | Roest-v2 | | Roest-v2 | |
|-------------|---------|---------|---------|---------|---------|---------|---------|---------|
| LM | No | | Yes | | No | | Yes | |
|-------------|---------|---------|---------|---------|---------|---------|---------|---------|
| Dialect | CER (%) | WER (%) | CER (%) | WER (%) | CER (%) | WER (%) | CER (%) | WER (%) |
| Vestjysk | 12.7 | 37.1 | 10.1 | 26.3 | 12.2 | 36.3 | 9.82 | 25.2 |
| Sønderjysk | 14.7 | 37.8 | 11.9 | 26.0 | 14.2 | 36.2 | 11.6 | 25.4 |
| Bornholmsk | 9.32 | 29.9 | 6.79 | 17.7 | 8.08 | 26.7 | 6.12 | 15.7 |
| Østjysk | 5.51 | 18.7 | 3.97 | 11.7 | 5.39 | 18.0 | 4.06 | 11.3 |
| Nordjysk | 3.86 | 13.6 | 2.57 | 7.72 | 3.80 | 13.5 | 2.75 | 7.51 |
| Københavnsk | 5.27 | 18.8 | 3.31 | 10.2 | 5.02 | 17.7 | 3.20 | 9.98 |
| Fynsk | 9.41 | 28.6 | 7.43 | 18.3 | 8.86 | 27.0 | 7.20 | 17.7 |
| Non-native | 10.6 | 33.2 | 7.84 | 20.9 | 10.0 | 31.6 | 7.46 | 19.4 |
| Sjællandsk | 5.82 | 19.5 | 4.44 | 12.6 | 5.70 | 18.6 | 4.48 | 12.7 |
| Sydømål | 7.09 | 20.7 | 6.38 | 14.9 | 6.96 | 20.4 | 6.44 | 15.3 |
### Performance on Other Datasets
The model was also tested against other datasets to evaluate generalizability:
| | **Roest-wav2vec2-315M-v1** | | **Roest-wav2vec2-315M-v2** | |
| ------------------------------------------------------------------------------------- | ----------- | ----- | ----------- | -------- |
| Evaluation Dataset | WER % | CER % | WER % | CER % |
| [CoRal](https://huggingface.co/datasets/alexandrainst/coral/viewer/read_aloud/test) | 17.0 | 6.6 | **16.3** | **6.5** |
| [NST-da](https://huggingface.co/datasets/alexandrainst/nst-da) | 29.7 | 13.9 | **26.1** | **11.9** |
| [CommonVoice17](https://huggingface.co/datasets/mozilla-foundation/common_voice_17_0) | 16.7 | 6.6 | **14.4** | **5.4** |
| [Fleurs-da_dk](https://huggingface.co/datasets/google/fleurs) | 27.3 | 7.9 | **26.4** | **7.7** |
| [Fleurs-da_dk](https://huggingface.co/datasets/google/fleurs) Normed | 16.6 | 6.3 | **15.6** | **6.1** |
**OBS!** The vocab used for training incudes numerals (0,1,2,..,9), which are translated to text in a post-processing step. If the model misses spaces the numbers are interpreted as one, which expecially affects the NST score as this dataset contains many numerals.
---
## Training curves
---
## Creators and Funders
This model has been trained and the model card written by Marie Juhl Jørgensen and Søren Vejlgaard Holm at [Alvenir](https://www.alvenir.ai/).
The CoRal project is funded by the [Danish Innovation Fund](https://innovationsfonden.dk/) and consists of the following partners:
- [Alexandra Institute](https://alexandra.dk/)
- [University of Copenhagen](https://www.ku.dk/)
- [Agency for Digital Government](https://digst.dk/)
- [Alvenir](https://www.alvenir.ai/)
- [Corti](https://www.corti.ai/)
We would like specifically to thank Dan Saattrup Nielsen, Alexandra Institute for (among other things) the repository work and Simon Leminen Madsen, Alexandra Institute for modelling work.
## Citation
We will submit a research paper soon, but until then, if you use this model in your research or development, please cite it as follows:
@misc{roest-wav2vec2-315m-v2,
author = {Marie Juhl Jørgensen, Søren Vejlgaard Holm, Martin Carsten Nielsen, Dan Saattrup Nielsen, Sif Bernstorff Lehmann, Simon Leminen Madsen, Anders Jess Pedersen, Anna Katrine van Zee, Anders Søgaard and Torben Blach},
title = {Roest-wav2vec-315m-v2: A Danish state-of-the-art speech recognition model trained on varied demographics and dialects},
year = {2025},
url = {https://huggingface.co/CoRal-project/roest-wav2vec2-315m-v2},
}