Datasets:
language:
- vi
license: cc-by-nc-sa-4.0
multilinguality: monolingual
size_categories:
- n<1K
source_datasets:
- linhtran92/viet_bud500
task_categories:
- automatic-speech-recognition
tags:
- vietnamese
- benchmark
- quantization
- asr
- wer
- cer
- calibration
- evaluation
- audio
- speech
pretty_name: ViASR-Bench
dataset_info:
features:
- name: id
dtype: string
- name: transcript
dtype: string
- name: duration_s
dtype: float32
- name: sampling_rate
dtype: int32
- name: source_split
dtype: string
- name: audio
dtype:
audio:
sampling_rate: 16000
splits:
- name: calibration
num_examples: 256
- name: evaluation
num_examples: 600
download_size: 73400320
dataset_size: 73400320
ViASR-Bench 🇻🇳🎙️
Vietnamese benchmark dataset for ASR model quantization — providing both a calibration set and an evaluation set.
ViASR-Bench is a curated sample from BUD500, the largest public Vietnamese podcast speech dataset. It is designed specifically for the two-phase lifecycle of ASR quantization:
| Phase | Split | Purpose |
|---|---|---|
| Calibration | calibration (256 utterances) |
Feed to AWQ / GPTQ / SmoothQuant to compute activation statistics and compensation factors |
| Evaluation | evaluation (600 utterances) |
Measure WER / CER degradation after quantization |
Important: This dataset is a subsample of BUD500, not a standalone corpus. Audio content is sourced from BUD500 (CC-BY-NC-SA 4.0) and is intended for non-commercial research use only.
Dataset Summary
| Split | Utterances | Duration | Size (~) | Source in BUD500 |
|---|---|---|---|---|
calibration |
256 | ~10.9 min | ~21 MB | train split |
evaluation |
600 | ~25.6 min | ~49 MB | test split |
| Total | 856 | ~36.5 min | ~70 MB |
Audio format: 16 kHz · Mono · PCM-16 (WAV)
Utterance duration statistics:
| Split | Mean (s) | Median (s) | P10 (s) | P90 (s) | Max (s) |
|---|---|---|---|---|---|
| calibration | 2.56 | 2.12 | 1.10 | 4.48 | 19.2 |
| evaluation | 2.56 | 2.11 | 1.09 | 4.52 | 19.8 |
Motivation
Why a Vietnamese-specific ASR quantization benchmark?
Existing quantization tools (AWQ, GPTQ, SmoothQuant) require a calibration dataset whose acoustic distribution matches the target language. Using English speech data to calibrate a Vietnamese ASR model leads to suboptimal quantization because:
6-tone tonal system. Vietnamese has six tones (ngang, huyền, sắc, hỏi, ngã, nặng) that create unique patterns in mel-spectrograms and encoder feature spaces, distinct from non-tonal languages.
Regional dialect variation. Three major dialects (Northern, Central, Southern) differ significantly in formant distributions and prosody, affecting attention and convolution layers in ASR encoders.
Monosyllabic structure. Vietnamese is predominantly monosyllabic, producing different sequence-length and attention-pattern distributions than English.
Calibrating on English audio leaves these activation patterns unrepresented, degrading quantization quality specifically for Vietnamese phonemes.
Why CER over WER for Vietnamese?
Vietnamese words average 1.7–2.2 characters, making tone confusion errors (e.g., khoẻ → khoề: a single diacritic change) inflate WER disproportionately:
Reference: "bạn có khoẻ không" (4 words, 15 chars)
Hypothesis: "bạn có khoề không"
WER = 1/4 = 25.0% ← one wrong word
CER = 1/15 = 6.7% ← one wrong character
CER is a more sensitive and fair metric for detecting tone-level degradation caused by quantization on Vietnamese. Both WER and CER are reported.
Source Data: BUD500
BUD500 is the largest public Vietnamese speech dataset (~500 hours of podcast audio with manually verified transcripts, covering diverse topics and all three major dialects).
| Property | Value |
|---|---|
| Total duration | ~500 hours |
| Utterances | ~150,000 |
| Sampling rate | 16,000 Hz |
| Content type | Podcast (multi-topic) |
| Dialect coverage | Northern, Central, Southern |
| HuggingFace ID | linhtran92/viet_bud500 |
| License | CC-BY-NC-SA 4.0 |
Why BUD500 over alternatives?
| Dataset | Hours | Quality | Diversity | Public |
|---|---|---|---|---|
| BUD500 | ~500h | High | High | ✅ |
| VIVOS | 15h | High | Low (read speech) | ✅ |
| FLEURS vi | ~10h | Medium | Medium | ✅ |
| CommonVoice vi | ~30h | Medium | Medium | ✅ |
| VLSP | 100h+ | High | High | ❌ |
BUD500's size ensures that random sampling still yields diverse coverage. Its podcast format is closer to real-world deployment conditions than studio read-speech datasets like VIVOS.
Sampling Methodology
Non-overlapping splits
Calibration and evaluation sets are guaranteed non-overlapping by transcript:
eval_transcripts = {s["transcript"] for s in eval_samples}
# Calibration: skip any utterance whose transcript appears in eval
if transcript in eval_transcripts:
continue
This prevents data leakage between calibration and evaluation.
Quality filter
Each utterance passes a 2-condition filter:
keep(u) = True iff:
1.0s ≤ duration(u) ≤ 20.0s # remove noise clips and unusually long segments
AND len(transcript(u)) > 0 # non-empty transcript
Sampling procedure
1. Stream BUD500 (streaming=True) — no full download required
2. Collect buffer = 5× target size from filtered utterances
3. random.sample(buffer, n_target, seed=42) — fixed seed for reproducibility
Calibration is drawn from BUD500 train split (seed=43).
Evaluation is drawn from BUD500 test split (seed=42).
Transcript normalization
All transcripts are stored in Unicode NFC normalized form. Before computing WER/CER, apply the same normalization to model hypotheses:
import unicodedata, re
def normalise_vi(text: str) -> str:
text = unicodedata.normalize("NFC", text) # critical for Vietnamese diacritics
text = text.lower()
text = re.sub(r"[^\w\s]", " ", text, flags=re.UNICODE)
text = re.sub(r"\s+", " ", text).strip()
return text
NFC normalization is critical because Vietnamese characters can be encoded two ways:
- Decomposed:
e+ combining hook above + combining dot below - Precomposed: single codepoint
ệ
Without normalization, visually identical strings may have non-zero edit distance.
Usage
Installation
pip install datasets soundfile jiwer transformers torch tqdm numpy
Load the dataset
from datasets import load_dataset
# Evaluation split
eval_ds = load_dataset("your-org/vi-asr-bench", split="evaluation")
# Calibration split
calib_ds = load_dataset("your-org/vi-asr-bench", split="calibration")
# Each sample:
# {
# "id": "sample_0042",
# "audio": {"array": np.ndarray, "sampling_rate": 16000},
# "transcript": "xin chào thế giới",
# "duration_s": 3.21,
# "source_split": "test"
# }
AWQ / GPTQ Calibration
import torch
from datasets import load_dataset
calib_ds = load_dataset("your-org/vi-asr-bench", split="calibration")
# Extract audio arrays for the encoder
audio_inputs = [
torch.tensor(sample["audio"]["array"]).unsqueeze(0) # (1, T)
for sample in calib_ds
]
# Feed into your quantization calibration loop:
# for audio in audio_inputs:
# model.encoder(audio) # collect activation statistics
WER / CER Evaluation
import unicodedata, re
from datasets import load_dataset
from jiwer import wer, cer
from transformers import pipeline
def normalise_vi(text):
text = unicodedata.normalize("NFC", text)
text = text.lower()
text = re.sub(r"[^\w\s]", " ", text, flags=re.UNICODE)
return re.sub(r"\s+", " ", text).strip()
eval_ds = load_dataset("your-org/vi-asr-bench", split="evaluation")
asr_pipe = pipeline("automatic-speech-recognition",
model="your-quantized-model",
generate_kwargs={"language": "vi", "task": "transcribe"})
references = [normalise_vi(s["transcript"]) for s in eval_ds]
hypotheses = [normalise_vi(r["text"]) for r in asr_pipe(
[s["audio"] for s in eval_ds], batch_size=8)]
print(f"WER: {wer(references, hypotheses)*100:.2f}%")
print(f"CER: {cer(references, hypotheses)*100:.2f}%")
Compare quantized vs. baseline
python vi_asr_eval.py \
--model openai/whisper-large-v3 \
--compare your-org/whisper-large-v3-int4 \
--output results.json
Expected output format:
================================================================
Metric openai/whisper-large-v3 your-org/...-int4 Delta
----------------------------------------------------------------
WER 8.24% 8.91% +0.67%
CER 3.11% 3.38% +0.27%
Reproducibility
Full metadata is stored in metadata.json for each split:
{
"split": "evaluation",
"n_samples": 600,
"seed": 42,
"source": "linhtran92/viet_bud500",
"source_split": "test",
"sampling_rate": 16000,
"total_duration_s": 1536.0,
"total_duration_min": 25.6,
"total_size_mb": 49.1,
"filter": {"min_dur_s": 1.0, "max_dur_s": 20.0},
"normalization": "unicode_nfc"
}
Relation to ViWiki-Bench
ViASR-Bench is the speech counterpart of ViWiki-Bench (Vietnamese LLM benchmark). Together they form a complete Vietnamese quantization benchmark suite:
| ViWiki-Bench (LLM) | ViASR-Bench (ASR) | |
|---|---|---|
| Input modality | Text (token IDs) | Audio (float32 arrays) |
| Calibration | 128 sequences from Wikipedia vi | 256 utterances from BUD500 train |
| Evaluation | ~280k tokens from Wikipedia vi | 600 utterances from BUD500 test |
| Metric | Perplexity (PPL) | WER / CER |
| Source dataset | wikimedia/wikipedia 20231101.vi |
linhtran92/viet_bud500 |
Limitations
- Single source: Only BUD500 (podcast). Read speech (VIVOS), spontaneous conversation, and children's speech are not represented.
- No dialect labels: BUD500 does not tag individual utterances with Northern/Central/Southern dialect, so stratified sampling by dialect is not possible.
- Small evaluation set: 600 utterances (~26 min) is sufficient for relative comparison between quantization methods, but not for high-precision absolute WER estimation (vs. LibriSpeech test-clean at 5.4 hours).
- Non-commercial license: Inherited from BUD500 (CC-BY-NC-SA 4.0). Not suitable for commercial product deployment.
Citation
If you use ViASR-Bench in your research, please cite both this dataset and BUD500:
@techreport{viasr_bench2024,
title = {ViASR-Bench: A Vietnamese Benchmark Dataset for
ASR Model Quantization Calibration and Evaluation},
author = {AnhND},
year = {2026},
note = {Technical Report v1.0. Sampled from linhtran92/viet\_bud500},
url = {https://huggingface.co/datasets/your-org/vi-asr-bench}
}
@dataset{bud500,
title = {BUD500: A Large-Scale Vietnamese Podcast Speech Dataset},
author = {Linh Tran},
publisher = {HuggingFace},
url = {https://huggingface.co/datasets/linhtran92/viet_bud500}
}
License
This dataset inherits the license of its source: CC-BY-NC-SA 4.0 (Non-Commercial).
The sampling and evaluation code is released under MIT License.