Noise-Robust Target-Speaker Voice Activity Detection Through Self-Supervised Pretraining
Holger Severin Bovbjerg, Jan Østergaard, Jesper Jensen, Zheng-Hua Tan
TL;DR
This work targets robust detection of target-speaker speech in noisy environments by combining a causal self-supervised pretraining stage, DN-APC, with a speaker-conditioned TS-VAD model. DN-APC pretrained Conformer-based TS-VAD encoders yield about a 2% gain in average performance for both seen and unseen noise, particularly boosting speech-vs-noise discrimination. The study systematically compares five speaker-conditioning methods (including FiLM and embedding preprocessing) and finds FiLM generally offers the best overall outcomes, with multiplication excelling for target-speech detection; embedding preprocessing can provide marginal gains. Representation analysis via t-SNE shows DN-APC pretraining captures robust speech vs non-speech structure prior to fine-tuning, underscoring SSL’s value for noise-robust TS-VAD systems and potential gains in real-world diarization and ASR pipelines.
Abstract
Target-Speaker Voice Activity Detection (TS-VAD) is the task of detecting the presence of speech from a known target-speaker in an audio frame. Recently, deep neural network-based models have shown good performance in this task. However, training these models requires extensive labelled data, which is costly and time-consuming to obtain, particularly if generalization to unseen environments is crucial. To mitigate this, we propose a causal, Self-Supervised Learning (SSL) pretraining framework, called Denoising Autoregressive Predictive Coding (DN-APC), to enhance TS-VAD performance in noisy conditions. We also explore various speaker conditioning methods and evaluate their performance under different noisy conditions. Our experiments show that DN-APC improves performance in noisy conditions, with a general improvement of approx. 2% in both seen and unseen noise. Additionally, we find that FiLM conditioning provides the best overall performance. Representation analysis via tSNE plots reveals robust initial representations of speech and non-speech from pretraining. This underscores the effectiveness of SSL pretraining in improving the robustness and performance of TS-VAD models in noisy environments.
