Synthetic Only Whisper Small Synthetic Only Small Constwarmup Best5750 Checkpoint

Summary

This repository contains a Whisper checkpoint for Chichewa/Nyanja automatic speech recognition, fine-tuned from openai/whisper-small.

• Experiment type: synthetic-only
• Base model: openai/whisper-small
• Training condition: synthetic_only_small_constwarmup_best5750
• Release artifact: full fine-tuned checkpoint selected from the best training checkpoint

Intended use

This checkpoint is intended for research and evaluation on Chichewa/Nyanja ASR. It is not a production-ready speech system and should be validated carefully before downstream use.

How to use

This repository contains a full fine-tuned checkpoint. It can be loaded directly with Transformers.

from transformers import AutoModelForSpeechSeq2Seq, AutoProcessor

model_id = "ai4good-labyrinth/synthetic-only-whisper-small-no-language-v2"
processor = AutoProcessor.from_pretrained(model_id)
model = AutoModelForSpeechSeq2Seq.from_pretrained(model_id)

Training data

• Training source: Prepared dataset
• Evaluation source during training: FLEURS dev
• Train examples before duration filtering: 374612
• Train examples after duration filtering: 374576
• Dev examples before duration filtering: 311
• Dev examples after duration filtering: 305
• Duration filter used during training: min_duration_seconds=0.0, max_duration_seconds=30.0

Training procedure

• Fine-tuning script: experiments/whisper_finetune/finetune_whisper.py
• Base model: openai/whisper-small
• Task: transcribe
• Language hint during training/evaluation: none, corresponding to --language auto in standalone evaluation
• Mixed precision: fp16
• Gradient checkpointing: True
• Selected checkpoint step: 5750
• Selected checkpoint epoch: 0.12

Training-time dev selection

The best checkpoint was selected using trainer-side dev evaluation on the duration-filtered FLEURS dev split.

• Dev WER: 0.7279
• Dev CER: 0.2526
• Dev loss: 1.5864

These values come from the training pipeline and may differ slightly from standalone post-hoc evaluation because the decoding path is not perfectly identical.

Evaluation protocol

Standalone evaluation is recommended for the final release. Filtered and unfiltered results should be reported separately.

• Filtered evaluation: min_duration_seconds=0, max_duration_seconds=30
• Unfiltered evaluation: no duration constraint
• Decoding task: transcribe
• Language hint: auto

Evaluation summary

Files in this repository

• Model weights and config: repository root
• Processor/tokenizer files: repository root
• Evaluation JSON files: eval/...

Known limitations

• Whisper does not provide an official Nyanja/Chichewa language token.
• Users must also comply with the upstream dataset licenses and any upstream model license obligations.
• Standalone evaluation and trainer-side evaluation can differ slightly even on the same split and duration filter.
• Cross-dataset results should be interpreted carefully because transcription conventions may differ across corpora.

Citation

If you use this checkpoint, please cite:

• the Whisper paper
• the FLEURS dataset
• this repository

@misc{synthetic_only_whisper_small_no_language_v2_2026,
  title        = {Synthetic Only Whisper Small Synthetic Only Small Constwarmup Best5750 Checkpoint},
  author       = {AI4Good Labyrinth Team},
  year         = {2026},
  howpublished = {\url{https://huggingface.co/ai4good-labyrinth/synthetic-only-whisper-small-no-language-v2}},
  note         = {Whisper fine-tuning for Chichewa/Nyanja ASR}
}