license: apache-2.0
task_categories:
- text-to-speech
- automatic-speech-recognition
language:
- suk
tags:
- sukuma
- tts
- speech-synthesis
- low-resource
- evaluation
size_categories:
- 1K<n<10K
dataset_info: features: - name: audio dtype: audio - name: text dtype: string - name: gender dtype: string - name: voice dtype: string - name: filename dtype: string - name: record_id dtype: string splits: - name: train num_examples: 3257 - name: test num_examples: 362 - name: test_indistribution_synthesis num_examples: 362 - name: test_outdistribution_synthesis num_examples: 362 download_size: 6725563759 dataset_size: 6935373055 configs: - config_name: default data_files: - split: train path: data/train-* - split: test path: data/test-* - split: test_indistribution_synthesis path: data/test_indistribution_synthesis-* - split: test_outdistribution_synthesis path: data/test_outdistribution_synthesis-* license: cc-by-4.0 language: - suk task_categories: - automatic-speech-recognition - text-to-speech - speech-synthesis tags: - sukuma - low-resource - african-languages - bantu - tanzania - speech-corpus - speech-evaluation - tts-evaluation size_categories: - 1K<n<10K pretty_name: Sukuma Voices
Sukuma Voices Dataset 🎙️
The first publicly available speech corpus for Sukuma (Kisukuma), a Bantu language spoken by approximately 10 million people in northern Tanzania. This dataset supports speech-to-text, text-to-speech, and speech evaluation tasks.
Dataset Description
Sukuma Voices addresses the critical gap in speech technology resources for one of Africa's most severely under-resourced languages. The dataset includes both human recordings and TTS-synthesized audio for comprehensive model evaluation.
Dataset Summary
| Metric | Value |
|---|---|
| Total Samples | 4,343 |
| Total Duration | 19.56 hours |
| Average Duration | 10.25 ± 4.15 seconds |
| Duration Range | 1.40 - 30.36 seconds |
| Total Words | 140,325 |
| Unique Vocabulary | 21,366 |
| Average Words/Sample | 20.4 |
| Speaking Rate | 121.6 WPM |
Supported Tasks
- Automatic Speech Recognition (ASR): Converting Sukuma speech to text
- Text-to-Speech (TTS): Synthesizing natural-sounding Sukuma speech
- Speech Evaluation: Comparing human vs. synthesized speech quality
- Cross-lingual Speech Processing: Research between Swahili and Sukuma
Languages
- Sukuma (ISO 639-3:
suk) - A Bantu language of the Niger-Congo family
Dataset Structure
Splits Overview
| Split | Samples | Description |
|---|---|---|
train |
3,257 | Human recordings for training |
test |
362 | Human recordings for evaluation |
test_indistribution_synthesis |
362 | TTS-generated audio (in-distribution) |
test_outdistribution_synthesis |
362 | TTS-generated audio (out-of-distribution) |
Split Details
| Split | Purpose | Audio Source |
|---|---|---|
| train | Model training | Human recordings |
| test | ASR/TTS evaluation on natural speech | Human recordings |
| test_indistribution_synthesis | Evaluate TTS quality on seen text patterns | TTS-generated |
| test_outdistribution_synthesis | Evaluate TTS generalization | TTS-generated |
Features
All subsets contain the following features:
| Feature | Type | Description |
|---|---|---|
audio |
Audio | Speech samples (16kHz for ASR, 24kHz for TTS) |
text |
String | Text content in Sukuma language |
gender |
String | Speaker gender |
voice |
String | Voice identifier |
filename |
String | Original filename |
record_id |
String | Unique record identifier |
Example Instance
{
"audio": {
"array": [...],
"sampling_rate": 16000
},
"text": "Umunhu ngwunuyo agabhalelaga chiza abhanhu bhakwe.",
"gender": "female",
"voice": "speaker_01",
"filename": "sukuma_001.wav",
"record_id": "suk_00001"
}
Example Sentences
| Language | Text |
|---|---|
| Sukuma | Umunhu ngwunuyo agabhalelaga chiza abhanhu bhakwe, kunguyo ya kikalile kakwe akagubhatogwa na gubhambilija abho bhali mumakoye. |
| English | This person raises his people well, because of his good behavior, of loving people and helping his colleagues who are in trouble, in their lives. |
Usage
Loading the Dataset
from datasets import load_dataset
# Load all splits
dataset = load_dataset("sartifyllc/SUKUMA_VOICE")
# Access specific splits
train_data = dataset["train"]
test_data = dataset["test"]
test_synth_in = dataset["test_indistribution_synthesis"]
test_synth_out = dataset["test_outdistribution_synthesis"]
print(f"Train samples: {len(train_data)}")
print(f"Test samples: {len(test_data)}")
ASR Training Example
from datasets import load_dataset
from transformers import WhisperProcessor, WhisperForConditionalGeneration
# Load dataset
dataset = load_dataset("sartifyllc/SUKUMA_VOICE")
# Load model
processor = WhisperProcessor.from_pretrained("openai/whisper-large-v3")
model = WhisperForConditionalGeneration.from_pretrained("openai/whisper-large-v3")
# Process a sample
sample = dataset["test"][0]
input_features = processor(
sample["audio"]["array"],
sampling_rate=16000,
return_tensors="pt"
).input_features
# Generate transcription
predicted_ids = model.generate(input_features)
transcription = processor.batch_decode(predicted_ids, skip_special_tokens=True)[0]
print(f"Predicted: {transcription}")
print(f"Reference: {sample['text']}")
TTS Evaluation Example
from datasets import load_dataset
from jiwer import wer
# Load human and synthesized test sets
dataset = load_dataset("sartifyllc/SUKUMA_VOICE")
human_test = dataset["test"]
synth_test = dataset["test_indistribution_synthesis"]
# Compare WER between human and synthesized speech
# (using your trained ASR model)
human_wer = evaluate_asr(model, human_test)
synth_wer = evaluate_asr(model, synth_test)
print(f"Human Speech WER: {human_wer:.2%}")
print(f"Synthesized Speech WER: {synth_wer:.2%}")
Dataset Creation
Source Data
The dataset was curated from audio recordings and textual transcriptions of the Sukuma New Testament 2000 translation, sourced from the Bible.com platform.
Why Biblical Text?
- Standardized orthographic conventions ensuring transcription consistency
- Diverse linguistic structures encompassing narrative, dialogue, and theological discourse
- Cultural relevance to Sukuma-speaking communities
- Availability of both audio recordings and verified textual transcriptions
Synthesis Pipeline
The test_indistribution_synthesis and test_outdistribution_synthesis splits were generated using our Sukuma-TTS model, fine-tuned on Orpheus 3B with LoRA.
Annotations
The data was rigorously annotated to ensure phonetic and orthographic consistency, with validation by native Sukuma speakers.
Baseline Results
ASR Performance (Whisper Large V3)
| Metric | Human Speech | Synthesized Speech |
|---|---|---|
| Final WER | 25.19% | 32.60% |
| Min WER | 22.01% | 29.97% |
| WER Reduction | 82.94% | 78.93% |
Key Findings:
- Strong correlation between human and synthetic learning curves (Pearson's r = 0.997)
- Performance gap narrows as training progresses (from 9.97 to 8.11 WER points)
- Synthetic speech captures essential acoustic-phonetic characteristics despite ~28% relative performance gap
TTS Performance (Orpheus 3B v0.1)
| Metric | Score |
|---|---|
| Mean Opinion Score (MOS) | 3.9 ± 0.15 |
| Human Recording MOS | 4.6 ± 0.1 |
Evaluated by native Sukuma speakers using a 5-point Likert scale.
Considerations for Using the Data
Known Limitations
- Domain Specificity: Data is primarily from biblical texts, which may not fully represent everyday conversational Sukuma
- Diacritic Variations: Sukuma has two written forms (with and without diacritics); this dataset focuses on the non-diacritic version
- Single Source: Limited speaker diversity from a single recording source
Linguistic Challenges
- Sukuma is a tonal language with complex phonological features
- The language lacks standardized orthographic conventions across written materials
- Diacritic and non-diacritic text representations can affect vocabulary size and evaluation metrics
Personal and Sensitive Information
The dataset contains religious text (Bible readings) and does not include personal or sensitive information about individuals.
Citation
If you use this dataset, please cite:
@inproceedings{mgonzo2025sukuma,
title={Learning from Scarcity: Building and Benchmarking Speech Technology for Sukuma},
author={Mgonzo, Macton and Oketch, Kezia and Etori, Naome and Mang'eni, Winnie and Nyaki, Elizabeth and Mollel, Michael S.},
booktitle={Proceedings of the Association for Computational Linguistics},
year={2025}
}
Additional Information
Authors
| Name | Affiliation | Contact |
|---|---|---|
| Macton Mgonzo | Brown University | macton_mgonzo@brown.edu |
| Kezia Oketch | University of Notre Dame | |
| Naome Etori | University of Minnesota - Twin Cities | |
| Winnie Mang'eni | Pawa AI | |
| Elizabeth Nyaki | Pawa AI, Sartify Company Limited | |
| Michael S. Mollel | Sartify Company Limited |
Dataset Curators
Acknowledgments
We would like to express our gratitude to Sartify Company Limited and Pawa AI for their instrumental role in initiating this project and for providing the data access necessary to develop and evaluate our models. We also extend our sincere thanks to all the volunteers who generously dedicated their time to the evaluation process.
Licensing Information
This dataset is released under CC-BY-4.0.
Contributions
We welcome contributions to expand and improve this dataset! Areas of interest include:
- Additional Sukuma speech data beyond religious content
- Conversational and everyday language recordings
- Multi-speaker recordings
- Diacritic-annotated transcriptions
Ethical Considerations
- Consent was obtained from all human participants involved in data annotation
- Participants were informed about the technology's limitations and potential impacts
- The authors acknowledge that models trained on this data may inherit biases present in the source material
Related Resources
- 🤖 TTS Model: Mollel/Sukuma-TTS
- 📂 GitHub: sukuma-voices
This dataset represents an important step toward inclusive speech technology for African languages.