Wav2Vec2 Home-Domain SSL — HindiBabyNet

Self-supervised continued pretraining of facebook/wav2vec2-base on naturalistic Hindi parent–infant home interaction recordings from the HindiBabyNet corpus.

Model Description

This model adapts the wav2vec2-base speech representation to the home-recording domain — noisy, reverberant, multi-speaker environments with infant vocalisations and Hindi child-directed speech (CDS). The goal is to learn robust latent audio representations that better capture the acoustic characteristics of naturalistic home environments, which differ substantially from the read/broadcast speech used to train the original wav2vec2-base.

The model was pretrained using the standard wav2vec2 contrastive + diversity self-supervised objective (mask-and-predict on quantised latent speech frames), without any transcription labels.

Training Data

The model was trained on ~346 hours of naturalistic home recordings from the HindiBabyNet corpus — a collection of day-long audio recordings of Hindi-speaking parent–infant dyads in their home environment.

Audio characteristics:

• Long-form naturalistic recordings (minutes to hours per file)
• Multi-speaker: adults, infants, children, background voices
• Real-world noise: TV, kitchen, traffic, household appliances
• Reverberant home acoustics
• Child-directed speech, infant vocalisations, babbling

Training Procedure

Preprocessing

• Resampled to 16 kHz mono on-the-fly
• Random cropping: 8-second crops drawn randomly from long recordings (no chunk files saved to disk)
• Silence rejection: crops below RMS threshold 0.001 are re-sampled (up to 10 retries)
• Each file yields 10 random crops per epoch (epoch_multiplier=10)

Training Hyperparameters

Training Infrastructure

• Hardware: 4 × NVIDIA RTX 2080 Ti (11 GB VRAM each)
• Distributed: PyTorch DDP via torchrun
• Software: PyTorch 2.10, Transformers 5.1.0, torchaudio 2.10
• Training time: ~50,000 steps over ~3,333 effective epochs

Training Loss

The contrastive + diversity loss decreased consistently over training, indicating successful domain adaptation of the speech representations.

Intended Use

Primary Use Case

This model is intended as a feature extractor / encoder for downstream speech tasks on Hindi home-domain audio, such as:

• Automatic speech recognition (ASR) of child-directed speech
• Speaker diarisation in home recordings
• Infant vocalisation detection and classification
• Child language development research
• Acoustic event detection in home environments

How to Use

from transformers import Wav2Vec2Model, Wav2Vec2FeatureExtractor
import torch
import torchaudio

# Load model and feature extractor
model = Wav2Vec2Model.from_pretrained("arunps/wav2vec2-home-hindibabynet-ssl")
feature_extractor = Wav2Vec2FeatureExtractor.from_pretrained("arunps/wav2vec2-home-hindibabynet-ssl")

# Load and preprocess audio
waveform, sr = torchaudio.load("your_audio.wav")
if sr != 16000:
    waveform = torchaudio.functional.resample(waveform, sr, 16000)
waveform = waveform.mean(dim=0)  # mono

# Extract features
inputs = feature_extractor(waveform.numpy(), sampling_rate=16000, return_tensors="pt")
with torch.no_grad():
    outputs = model(**inputs)

# Last hidden state: (batch, time_frames, 768)
hidden_states = outputs.last_hidden_state

Fine-tuning for ASR

from transformers import Wav2Vec2ForCTC

model = Wav2Vec2ForCTC.from_pretrained(
    "arunps/wav2vec2-home-hindibabynet-ssl",
    ctc_loss_reduction="mean",
    pad_token_id=0,
    vocab_size=YOUR_VOCAB_SIZE,  # set to your tokenizer vocab
)
# Freeze feature extractor, fine-tune transformer + CTC head
model.freeze_feature_encoder()

Limitations

• Domain-specific: Optimised for Hindi home recordings; may not generalise well to studio/broadcast audio.
• No labels used: This is a self-supervised model — it has not been fine-tuned on any labelled task. Downstream fine-tuning is required for ASR, classification, etc.
• Language: Trained exclusively on Hindi home audio; cross-lingual transfer has not been evaluated.
• Noise: While the model is trained on noisy home audio (which may improve robustness), extreme noise conditions were not filtered out.

Ethical Considerations

• The training data consists of naturalistic home recordings of families with young children. All data collection was conducted under appropriate ethical review and informed consent.
• The model does not perform speech recognition or speaker identification on its own — it produces general-purpose speech representations.
• Users should ensure compliance with applicable data protection regulations when applying this model to new audio data.

Citation

If you use this model in your research, please cite:

@misc{wav2vec2-home-hindibabynet-ssl,
  author       = {Arun P S},
  title        = {Wav2Vec2 Home-Domain SSL for HindiBabyNet},
  year         = {2026},
  publisher    = {Hugging Face},
  url          = {https://huggingface.co/arunps/wav2vec2-home-hindibabynet-ssl}
}

Model Card Contact

Arun P S — Hugging Face profile