whisper-small-waxal-loo-lug · (leave-Luganda-out ablation)

⚠️ This is a research/ablation model, not a deployment model. It is Whisper-Small fine-tuned on 18 WAXAL languages EXCLUDING Luganda. It is used to measure novel-language transfer — how well a model does on Luganda, which it was never trained on. Do not use it for Luganda ASR (use the monolingual WAXAL model for that).

What this tests

WAXAL's headline finding is that in-language data is essential. Whisper (unlike Omnilingual) does not cover most WAXAL languages in pretraining, so it lets us ask a clean question with no forgetting confound: can training on sibling languages build a language the model never saw? Here Luganda has Bantu relatives (incl. Lingala and Shona) that Whisper itself was pretrained on.

Result — the novel-language transfer ladder for Luganda

Setting	WER	CER
Whisper zero-shot (base)	Unsupported (not in Whisper's 99 languages)	—
This model (trained on 18 siblings, Luganda held out)	86.4	32.0
Monolingual Whisper-Small (trained on Luganda)	21.6	—

The gap is stark: sibling training lands far above the monolingual model — training on neighbours cannot substitute for in-language data, even for a genuinely unseen language.

Training

Whisper-Small fine-tuned on the pooled train splits of the 18 non-Luganda WAXAL languages (google/WaxalNLP), balanced by capping each language, multilingual (no forced language token). 16 kHz mono; transcripts NFC-normalized + lower-cased, punctuation removed, diacritics preserved.

Hyperparameter	Value
Base	`openai/whisper-small` (244M)
Training languages	18 (all WAXAL except Luganda)
Utterances / language	3,000 (balanced)
Steps	4,000
Optimizer	AdamW, lr 1e-5, 200 warmup
Batch size	16
Precision	fp16
Hardware	1× H200

Languages it was trained on: Acholi, Akan, Amharic, Dagbani, Dagaare, Ewe, Fula, Ikposo, Lingala, Masaaba, Malagasy, Nyankole, Oromo, Sidama, Shona, Soga, Tigrinya, Wolaytta.

Evaluation

Scored on the held-out Luganda test split (jiwer WER/CER, NFC-normalized, lower-cased, diacritics preserved) — the same protocol as the rest of the benchmark.

Usage

from transformers import WhisperForConditionalGeneration, WhisperProcessor
import torch, soundfile as sf

model = WhisperForConditionalGeneration.from_pretrained("waxal-benchmarking/whisper-small-waxal-loo-lug")
processor = WhisperProcessor.from_pretrained("waxal-benchmarking/whisper-small-waxal-loo-lug")
wav, sr = sf.read("your_audio.wav")            # 16 kHz mono
feats = processor(wav, sampling_rate=16000, return_tensors="pt").input_features
ids = model.generate(feats)                    # multilingual; no forced language token
print(processor.batch_decode(ids, skip_special_tokens=True))

Intended and prohibited uses

Intended use. Research on, and development of, speech recognition for the language(s) this model was trained on, in particular for low-resource and under-served language communities. Error rates are still too high for high-stakes uses such as healthcare, legal, or emergency settings without further validation on the target domain.

Prohibited uses. This model must not be used for non-consensual applications, including surveillance or monitoring of individuals or communities, covert recording or transcription of people without their consent, or voice cloning and impersonation. Please respect the consent and privacy of the speakers whose speech you process.

Citation

Part of the WAXAL ASR Benchmark (arXiv:2606.02375).

@article{waxalnet2026,
  title  = {The WAXAL ASR Benchmark: Fine-Tuned Edge Models Across 19 African Languages},
  author = {Olufemi, Victor Tolulope and Babatunde, Oreoluwa and Njema, Ramsey and others},
  year   = {2026},
  note   = {arXiv preprint arXiv:2606.02375}
}