Whisper-Large-v3 Dutch - Common Voice Only (Baseline)
This model is a fine-tuned version of openai/whisper-large-v3 for Dutch automatic speech recognition (ASR). It was trained exclusively on Common Voice 17.0 Dutch without any synthetic data augmentation, serving as the baseline for evaluating the impact of synthetic speech in ASR training.
Introduction
Purpose
This baseline model demonstrates the performance achievable using only real, crowdsourced speech data from Common Voice 17.0. It serves as a reference point for comparing the effectiveness of synthetic data augmentation approaches, including:
Quality-filtered synthetic data (WAVe-based filtering)
Unfiltered synthetic data augmentation
Different quality thresholds and their impact on ASR performance
Training Approach
The model was fine-tuned from openai/whisper-large-v3 using standard supervised learning on Common Voice 17.0 Dutch:
Real Speech Only: Trained on 34,952 crowdsourced speech samples from Common Voice, with no synthetic augmentation.
Optimization: Trained for 5 epochs with a learning rate of 5e-6, global batch size of 256, and BF16 precision on an NVIDIA H200 GPU.
Checkpoint Selection: The best checkpoint was selected based on validation loss, occurring at step 250 with a validation loss of 0.0550.
This baseline achieves strong in-domain performance (4.39% Test WER on Common Voice) but shows limitations in cross-domain generalization (22.43% MLS WER), which synthetic data augmentation helps address.
Model Details
Property
Value
Base Model
openai/whisper-large-v3
Language
Dutch (nl)
Task
Automatic Speech Recognition (transcribe)
Parameters
1550M
Training Data
Common Voice 17.0 Dutch (Real Speech Only)
Total Training Samples
34,952
Sampling Rate
16kHz
Evaluation Results
This Model (whisper-large-v3-cv-only-nl)
Metric
Value
Validation Loss
0.0549
Validation WER
3.56%
Test WER (Common Voice)
4.39%
Test WER (MLS)
22.43%
Best Checkpoint
Step 250
Max Training Steps
680
Comparison with Synthetic Data Augmentation (Whisper-Large-v3 Dutch)
Training Data
Max Steps
Val Loss
Val WER
Test WER (CV)
Test WER (MLS)
MLS Improvement
Common Voice Only (Baseline)
680
0.0549
3.56%
4.39%
22.43%
—
High + Mixed Quality (q ≥ 0.5)
890
0.0520
3.57%
4.43%
20.29%
+9.5%
All Synthetic (Unfiltered)
1,365
0.0560
3.61%
4.44%
17.02%
+24.1%
Key Performance Characteristics
Fastest training: Fewest steps (680) among all configurations
Smallest dataset: Only 34,952 samples (no synthetic augmentation)
Strong in-domain: 4.39% Test WER on Common Voice
Limited cross-domain: 22.43% MLS WER (poorest generalization)
Reference baseline: Establishes performance without synthetic data
This baseline enables quantifying the value of synthetic speech:
Metric
CV-Only
+ Synthetic (best)
Improvement
Training Steps
680
1,365
+101%
Dataset Size
34,952
69,850
+100%
Test WER (CV)
4.39%
4.44%
-0.05pp
Test WER (MLS)
22.43%
17.02%
+24.1%
Key insight: Synthetic data augmentation maintains in-domain performance while dramatically improving cross-domain generalization, at the cost of increased training time.
Limitations
Domain specificity: Optimized for Common Voice-style speech; cross-domain performance limited
Acoustic diversity: Limited to Common Voice recording conditions and speaker pool
Data scarcity: No augmentation means model capacity may be underutilized
Generalization: 22.43% MLS WER shows difficulty adapting to different acoustic conditions
Citation
bibtex
1@article{perezhohin2024enhancing,
2 title={Enhancing Automatic Speech Recognition: Effects of Semantic Audio Filtering on Models Performance},
3 author={Perezhohin, Yuriy and Santos, Tiago and Costa, Victor and Peres, Fernando and Castelli, Mauro},
4 journal={IEEE Access},
5 year={2024},
6 publisher={IEEE}
7}
89@article{perezhohin2026wave,
10 title={WAVe: Word-aligned verification of synthetic speech for ASR},
11 author={Perezhohin, Yuriy and Castelli, Mauro},
12 journal={Information Sciences},
13 pages={123591},
14 year={2026},
15 publisher={Elsevier}
16}