  The integration of visual cues has revitalized the performance of the target
speech extraction task, elevating it to the forefront of the field.
Nevertheless, this multi-modal learning paradigm often encounters the challenge
of modality imbalance. In audio-visual target speech extraction tasks, the
audio modality tends to dominate, potentially overshadowing the importance of
visual guidance. To tackle this issue, we propose AVSepChain, drawing
inspiration from the speech chain concept. Our approach partitions the
audio-visual target speech extraction task into two stages: speech perception
and speech production. In the speech perception stage, audio serves as the
dominant modality, while visual information acts as the conditional modality.
Conversely, in the speech production stage, the roles are reversed. This
transformation of modality status aims to alleviate the problem of modality
imbalance. Additionally, we introduce a contrastive semantic matching loss to
ensure that the semantic information conveyed by the generated speech aligns
with the semantic information conveyed by lip movements during the speech
production stage. Through extensive experiments conducted on multiple benchmark
datasets for audio-visual target speech extraction, we showcase the superior
performance achieved by our proposed method.
