DSF-Net: Dual-strategy fusion for efficient audio-visual sound event localization and detection

Audio-visual sound event localization and detection (AVSELD) seeks to identify and locate sound-emitting objects by leveraging both audio and visual data. Current methods primarily rely on convolutional neural networks (CNNs), whose constrained receptive fields limit their ability to capture broader contextual information. Although Transformer-based architectures exhibit considerable proficiency in capturing global contextual information, their efficacy is impeded by the quadratic computational complexity associated with processing long-range dependencies. This poses a significant bottleneck, particularly in scenarios involving longer sequence lengths. To overcome this limitation, we propose DSF-Net, a novel neural network that introduces a dual-strategy fusion approach for the AVSELD task. Built upon an efficient state-space model backbone to ensure linear complexity, DSF-Net is designed for robust and computationally efficient multi-modal comprehension. The proposed dual strategies consist of: (1) an Adaptive Frequency Fusion module that aligns and integrates features in the frequency domain, and (2) an Audio-aware Aggregation module that performs advanced feature integration while considering the consistency between modalities. These strategies are embedded within a progressive fusion framework to enhance overall feature learning. Extensive experiments on the STARSS2023 dataset validate our dual-strategy approach, demonstrating that DSF-Net achieves state-of-the-art performance and outperforms existing methods. The source codes are publicly available at https://github.com/Devin-Pi/avseld-mamba.