CMOT: Cross-modal Mixup via Optimal Transport for Speech Translation

Yan Zhou, Qingkai Fang, Yang Feng


Abstract
End-to-end speech translation (ST) is the task of translating speech signals in the source language into text in the target language. As a cross-modal task, end-to-end ST is difficult to train with limited data. Existing methods often try to transfer knowledge from machine translation (MT), but their performances are restricted by the modality gap between speech and text. In this paper, we propose Cross-modal Mixup via Optimal Transport (CMOT) to overcome the modality gap. We find the alignment between speech and text sequences via optimal transport and then mix up the sequences from different modalities at a token level using the alignment. Experiments on the MuST-C ST benchmark demonstrate that CMOT achieves an average BLEU of 30.0 in 8 translation directions, outperforming previous methods. Further analysis shows CMOT can adaptively find the alignment between modalities, which helps alleviate the modality gap between speech and text.
Anthology ID:
2023.acl-long.436
Volume:
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2023
Address:
Toronto, Canada
Editors:
Anna Rogers, Jordan Boyd-Graber, Naoaki Okazaki
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
7873–7887
Language:
URL:
https://aclanthology.org/2023.acl-long.436
DOI:
10.18653/v1/2023.acl-long.436
Bibkey:
Cite (ACL):
Yan Zhou, Qingkai Fang, and Yang Feng. 2023. CMOT: Cross-modal Mixup via Optimal Transport for Speech Translation. In Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 7873–7887, Toronto, Canada. Association for Computational Linguistics.
Cite (Informal):
CMOT: Cross-modal Mixup via Optimal Transport for Speech Translation (Zhou et al., ACL 2023)
Copy Citation:
PDF:
https://aclanthology.org/2023.acl-long.436.pdf
Video:
 https://aclanthology.org/2023.acl-long.436.mp4