Efficient Audio-Visual Speech Separation with Discrete Lip Semantics and
  Multi-Scale Global-Local Attention
Authors: name: Kai Li; name: Kejun Gao; name: Xiaolin Hu
Published: 2025-09-28 03:25:34

Abstract: Audio-visual speech separation (AVSS) methods leverage visual cues to extract
target speech and have demonstrated strong separation quality in noisy acoustic
environments. However, these methods usually involve a large number of
parameters and require high computational cost, which is unacceptable in many
applications where speech separation serves as only a preprocessing step for
further speech processing. To address this issue, we propose an efficient AVSS
method, named Dolphin. For visual feature extraction, we develop DP-LipCoder, a
dual-path lightweight video encoder that transforms lip-motion into discrete
audio-aligned semantic tokens. For audio separation, we construct a lightweight
encoder-decoder separator, in which each layer incorporates a global-local
attention (GLA) block to efficiently capture multi-scale dependencies.
Experiments on three benchmark datasets showed that Dolphin not only surpassed
the current state-of-the-art (SOTA) model in separation quality but also
achieved remarkable improvements in efficiency: over 50% fewer parameters, more
than 2.4x reduction in MACs, and over 6x faster GPU inference speed. These
results indicate that Dolphin offers a practical and deployable solution for
high-performance AVSS in real-world scenarios. Our code and demo page are
publicly available at http://cslikai.cn/Dolphin/.