MAT-SED: A Masked Audio Transformer with Masked-Reconstruction Based Pre-training for Sound Event Detection
Pengfei Cai, Yan Song, Kang Li, Haoyu Song, Ian McLoughlin
TL;DR
This paper tackles sound event detection (SED) under limited labeled data by proposing MAT-SED, a pure Transformer-based architecture that uses masked-reconstruction pre-training for its context network and a global-local feature fusion to improve localization. The encoder (PaSST) provides strong latent representations, while the context network leverages Relative Positional Encoding to model temporal dependencies; pre-training on unlabeled data followed by mean-teacher semi-supervised fine-tuning enhances robustness and reduces overfitting. Key contributions include the first fully Transformer-based SED with self-supervised pre-training, an effective masked-reconstruction objective for temporal modeling, and a fusion strategy that integrates global and local cues for precise localization. Empirically, MAT-SED achieves PSDS1 = 0.587 and PSDS2 = 0.896 on DCASE2023 Task 4, surpassing prior methods and underscoring the potential of self-supervised pre-training for audio Transformers.
Abstract
Sound event detection (SED) methods that leverage a large pre-trained Transformer encoder network have shown promising performance in recent DCASE challenges. However, they still rely on an RNN-based context network to model temporal dependencies, largely due to the scarcity of labeled data. In this work, we propose a pure Transformer-based SED model with masked-reconstruction based pre-training, termed MAT-SED. Specifically, a Transformer with relative positional encoding is first designed as the context network, pre-trained by the masked-reconstruction task on all available target data in a self-supervised way. Both the encoder and the context network are jointly fine-tuned in a semi-supervised manner. Furthermore, a global-local feature fusion strategy is proposed to enhance the localization capability. Evaluation of MAT-SED on DCASE2023 task4 surpasses state-of-the-art performance, achieving 0.587/0.896 PSDS1/PSDS2 respectively.
