Pushing the Limits of Zero-shot End-to-End Speech Translation

Ioannis Tsiamas, Gerard Gállego, José Fonollosa, Marta Costa-jussà


Abstract
Data scarcity and the modality gap between the speech and text modalities are two major obstacles of end-to-end Speech Translation (ST) systems, thus hindering their performance. Prior work has attempted to mitigate these challenges by leveraging external MT data and optimizing distance metrics that bring closer the speech-text representations. However, achieving competitive results typically requires some ST data. For this reason, we introduce ZeroSwot, a method for zero-shot ST that bridges the modality gap without any paired ST data. Leveraging a novel CTC compression and Optimal Transport, we train a speech encoder using only ASR data, to align with the representation space of a massively multilingual MT model. The speech encoder seamlessly integrates with the MT model at inference, enabling direct translation from speech to text, across all languages supported by the MT model. Our experiments show that we can effectively close the modality gap without ST data, while our results on MuST-C and CoVoST demonstrate our method’s superiority over not only previous zero-shot models, but also supervised ones, achieving state-of-the-art results.
Anthology ID:
2024.findings-acl.847
Volume:
Findings of the Association for Computational Linguistics ACL 2024
Month:
August
Year:
2024
Address:
Bangkok, Thailand and virtual meeting
Editors:
Lun-Wei Ku, Andre Martins, Vivek Srikumar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
14245–14267
Language:
URL:
https://aclanthology.org/2024.findings-acl.847
DOI:
Bibkey:
Cite (ACL):
Ioannis Tsiamas, Gerard Gállego, José Fonollosa, and Marta Costa-jussà. 2024. Pushing the Limits of Zero-shot End-to-End Speech Translation. In Findings of the Association for Computational Linguistics ACL 2024, pages 14245–14267, Bangkok, Thailand and virtual meeting. Association for Computational Linguistics.
Cite (Informal):
Pushing the Limits of Zero-shot End-to-End Speech Translation (Tsiamas et al., Findings 2024)
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PDF:
https://aclanthology.org/2024.findings-acl.847.pdf