anquachdev/PhoMT-en-vi-speech

PhoMT EN–VI Parallel Speech

Synthetic parallel speech for English↔Vietnamese speech-to-speech translation research: 696,243 utterance pairs (~1,200 hours of Vietnamese speech + comparable English), generated from the sentence-aligned text pairs of PhoMT. Each row carries the English and Vietnamese text plus a spoken rendition of each side.

Rows	696,243
Vietnamese audio	48 kHz mono WAV, ~1,228 h total (mean ≈ 6.4 s/clip)
English audio	24 kHz mono WAV
Length balance	EN/VI duration ratio kept within 0.4–1.8

from datasets import load_dataset
ds = load_dataset("anquachdev/PhoMT-en-vi-speech", split="train", streaming=True)
row = next(iter(ds))  # en, vi, audio_en, audio_vi, duration_en_s, duration_vi_s, duration_ratio_en_vi

How it was generated

• Vietnamese: VieNeu-TTS v3-Turbo at 48 kHz.
• English: Kokoro-82M at 24 kHz.
• Voices, speaking speed, and target gender are assigned per row by a seeded deterministic RNG, so the corpus is exactly reproducible from the PhoMT indexes.

Speaker diversity via voice cloning

The Vietnamese voice pool contains 40 voices: 12 VieNeu presets plus 28 voices cloned from VIVOS speakers using VieNeu's reference-audio voice cloning. Every candidate voice passed a QA scorecard before entering the pool — transcription accuracy (PhoWhisper-small CER on synthesized calibration text), clone fidelity (speaker-embedding similarity to the reference), and speaking rate; 8 candidates that failed (unstable CER or dragging pace) were excluded.

Cross-lingual timbre matching

To keep speaker identity consistent across the language pair, each row's English voice is derived from its Vietnamese voice: both sides are embedded with VieNeu's 192-d speaker encoder (from synthesized calibration audio, not raw references), and the Vietnamese voice is matched to its nearest same-gender English candidate by cosine similarity. The English candidate grid holds 34 timbres — 7 Kokoro voices plus pairwise same-gender blends at 25/50/75 mixing weights — of which 14 are selected by the matching. Rows generated after this upgrade (51% of the corpus, PhoMT indexes ≥ 345600) use matched pairs; earlier rows pair voices independently.

Quality control

Every clip was validated before upload:

• Silence/corruption gate: each waveform decode-checked — non-finite or near-silent (RMS < 1e-4) output is regenerated (this catches rare GPU-decoder faults).
• Length-balance filter: pairs outside the 0.4–1.8 EN/VI duration ratio band were regenerated once with fresh sampling; pairs still out of band (genuinely imbalanced translations) were excluded.
• Upload integrity is tracked per source index in upload-state.json — every row maps to a unique PhoMT pair, with no duplicates.

Attribution

Text pairs from PhoMT (VinAI Research). Vietnamese voice references from VIVOS (AILAB, VNU-HCM). Speech synthesized with VieNeu-TTS and Kokoro-82M. The audio is fully synthetic; no human recordings are distributed in this dataset.