A Lightweight Framework for Online Voice Activity Detection in the Wild
Xuenan Xu, Heinrich Dinkel, Mengyue Wu, Kai Yu · 2021
Voice activity detection (VAD) is an essential pre-processing component for speech-related tasks such as automatic speech recognition (ASR).Traditional VAD systems require strong frame-level supervision for training, inhibiting their performance in real-world test scenarios.Previously, the generalpurpose VAD (GPVAD) framework has been proposed to enhance noise robustness significantly.However, GPVAD models are comparatively large and only work for offline evaluation.This work proposes the use of a knowledge distillation framework, where a (large, offline) teacher model provides framelevel supervision to a (light, online) student model.Our experiments verify that our proposed lightweight student models outperform GPVAD on all test sets, including clean, synthetic and real-world scenarios.Our smallest student model only uses 2.2% of the parameters and 15.9% duration cost of our teacher model for inference when evaluated on a Raspberry Pi.