Personal VAD 2.0 — B0 3-Layer LayerNorm LSTM Concat Personal VAD (wq2012/personal-vad-v2-lstm-concat)

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Open-Source Reproduction Notice: This model is part of an independent open-source reproduction of the Personal VAD 1.0 (Ding et al., Odyssey 2020) and Personal VAD 2.0 (Ding et al., INTERSPEECH 2022) papers. Because the original papers were developed using internal datasets and infrastructure, this model was trained from scratch using the open-source personal-vad library on our 8-language Multilingual LibriSpeech (MLS) benchmark (de, en, es, fr, it, nl, pl, pt, combining the 7 non-English facebook/multilingual_librispeech languages with OpenSLR 12 English LibriSpeech).

Model Summary

• Model ID: pvad2_b0_lstm_concat (wq2012/personal-vad-v2-lstm-concat)
• Paper: Personal VAD 2.0 (arXiv:2204.03793)
• Architecture: 256-d FC + 3-Layer LayerNorm LSTM (256 units) with d-vector input concatenation
• Backbone: lstm_v2
• Conditioning Mode: concat
• Loss Function: cross_entropy
• Trainable Parameters: 1,775,107
• Safetensors Checkpoint (model.safetensors): 6935.46 KB
• FP32 TFLite Flatbuffer (model_fp32.tflite): 7120.59 KB
• 8-Bit Quantized TFLite (model_quantized.tflite): 2012.16 KB
• Primary Concatenated Test Set micro-mAP: 0.7037 (Overall frame accuracy: 0.6027)

Included Files

• model.safetensors: Safetensors weights for secure, fast loading.
• model.weights.h5: Keras HDF5 checkpoint weights.
• model_config.json: Serialized personal_vad.ModelConfig spec.
• model_fp32.tflite: Unquantized 32-bit float stateful streaming TFLite flatbuffer (state_in -> (probs, state_out)).
• model_quantized.tflite: 8-bit dynamic-range quantized stateful streaming TFLite flatbuffer for on-device deployment.
• speaker_subspace.npz: Open-set regularized LDA+WCCN+PCA speaker subspace projection matrix (256-d L2-normalized d-vectors, full rank 256, trained from scratch on the 98 MLS training speakers).
• evaluation_metrics.json: Full test-set evaluation metrics on 40 unseen multilingual speakers (with utterance-cluster 95% bootstrap CIs).

Speaker Embedding (d-vector) Extractor Design & Transparency

In the original Personal VAD 1.0 and 2.0 papers, speaker embeddings (e_target) and frame-level cosine scores (s_t) were extracted using Google's internal 3-layer LSTM speaker verification network (4.88M parameters) trained with Generalized End-to-End (GE2E) loss on proprietary vendor-collected corpora.

To keep this open-source reproduction completely self-contained in pure TensorFlow/NumPy with zero external PyTorch/SpeechBrain/JAX dependencies, we trained our own lightweight, non-neural open-set 256-D speaker subspace extractor (OpenSetSpeakerSubspace, serialized in speaker_subspace.npz, 472.8 KB) from scratch on the 98 training speakers (1,159 utterances) of the 8-language Multilingual LibriSpeech (MLS) benchmark (16 unseen development speakers / 192 utterances; 40 unseen test speakers / 480 utterances):

1. 360-D Causal Multi-Resolution Acoustic Summary: Over voiced speech frames (or a strictly causal 14-frame / 140 ms sliding window for frame-level scores s_t), it extracts 40-D log-Mel [mean, std, pos_dev, neg_dev, delta_rms] (200-D) concatenated with 80-D log-Mel [mean, std] (160-D), while the Personal VAD network's acoustic input x_t remains 100% pure log-Mel filterbank energies.
2. 256-D Regularized LDA + WCCN + PCA Projection: Applies Z-score standardization, projects onto a full-rank 256-D discriminative subspace fitted via regularized Linear Discriminant Analysis (LDA), Within-Class Covariance Normalization (WCCN), and orthogonal PCA completion on the 98 training speakers, adds a fixed positive-cone offset on coordinate 255, and L2-normalizes the resulting vector (||e||_2 = 1).
3. Unseen-Speaker Verification Accuracy: On the 16 unseen development speakers (192 utterances), speaker_subspace.npz achieves an open-set speaker verification ROC-AUC of 0.9579, and on the 40 held-out unseen test speakers (480 utterances across 8 languages), it achieves a ROC-AUC of 0.9449 (mean positive cosine similarity 0.5424 vs. negative -0.0166). Users may also pass any external 256-D L2-normalized neural d-vector directly to PersonalVadModel or PersonalVadInferenceEngine.

Quickstart Usage

1. High-Level Audio Inference (personal_vad.load_pretrained)

import personal_vad

engine = personal_vad.load_pretrained("wq2012/personal-vad-v2-lstm-concat")
result = engine.infer_from_files(
    audio_path="conversation_16k.wav",
    enroll_path="target_speaker_enroll_16k.wav",
    use_tflite=False,
    threshold=0.5,
)
print("Summary:", result["summary"])
print("Probabilities shape:", result["probabilities"].shape)

2. On-Device Stateful 8-Bit Quantized .tflite Execution

from huggingface_hub import hf_hub_download
import numpy as np
import personal_vad

tflite_path = hf_hub_download(
    repo_id="wq2012/personal-vad-v2-lstm-concat", filename="model_quantized.tflite"
)
runner = personal_vad.TFLitePersonalVadRunner(tflite_path)
features = np.zeros((32, 512), dtype=np.float32)
speaker_embedding = np.ones((256,), dtype=np.float32) / np.sqrt(256.0)
cosine_score = np.full((32,), 0.8, dtype=np.float32)
probs = runner.predict(
    features=features,
    speaker_embedding=speaker_embedding,
    cosine_score=cosine_score,
    chunk_size=16,
)
print("TFLite output shape:", probs.shape)

Open-Source Multilingual LibriSpeech Benchmark Results

All models were trained on 98 training speakers (1,159 utterances) across 8 languages (de, en, es, fr, it, nl, pl, pt, combining the 7 non-English facebook/multilingual_librispeech languages with OpenSLR 12 English LibriSpeech), validated on 16 unseen dev speakers (192 utterances), and evaluated on 40 held-out unseen test speakers (480 utterances: 120 enrollment + 360 evaluation utterances, zero speaker overlap).

Personal VAD 1.0 Models (Concatenated Multi-Speaker Test Set)

Personal VAD 2.0 Models (Non-Concat & Concat Test Sets)

Per-Language Breakdown for pvad2_b0_lstm_concat (8 Languages)

Original Paper Reference Benchmarks

Personal VAD 1.0 (arXiv:1908.04284, Table 1)

Personal VAD 2.0 (arXiv:2204.03793, Table 1 & Table 2 Downstream ASR WER %)

Citation

@inproceedings{ding2020personal,
  title={Personal VAD: Speaker-Conditioned Voice Activity Detection},
  author={Ding, Shaojin and Wang, Quan and Chang, Shuo-yiin and Wan, Li and Moreno, Ignacio Lopez},
  booktitle={Proc. Odyssey The Speaker and Language Recognition Workshop},
  pages={433--439},
  year={2020}
}

@inproceedings{ding2022personal,
  title={Personal VAD 2.0: Optimizing Personal Voice Activity Detection for On-Device Speech Recognition},
  author={Ding, Shaojin and Rikhye, Rajeev and Liang, Qiao and He, Yanzhang and Wang, Quan and Narayanan, Arun and O'Malley, Tom and McGraw, Ian},
  booktitle={Proc. INTERSPEECH},
  pages={3744--3748},
  year={2022}
}