SONAR-SLT: Multilingual Sign Language Translation via Language-Agnostic Sentence Embedding Supervision
Yasser Hamidullah, Shakib Yazdani, Cennet Oguz, Josef Van Genabith, Cristina España-Bonet
Abstract
Sign language translation (SLT) is typically trained with text in a single spoken language, which limits scalability and cross-language generalization. Earlier approaches have replaced gloss supervision with text-based sentence embeddings, but up to now, these remain tied to a specific language and modality. In contrast, here we employ language-agnostic, multimodal embeddings trained on text and speech from multiple languages to supervise SLT, enabling direct multilingual translation. To address data scarcity, we propose a coupled augmentation method that combines multilingual target augmentations (i.e. translations into many languages) with video-level perturbations, improving model robustness. Experiments show consistent BLEURT gains over text-only sentence embedding supervision, with larger improvements in low-resource settings. Our results demonstrate that language-agnostic embedding supervision, combined with coupled augmentation, provides a scalable and semantically robust alternative to traditional SLT training.- Anthology ID:
- 2025.wmt-1.18
- Volume:
- Proceedings of the Tenth Conference on Machine Translation
- Month:
- November
- Year:
- 2025
- Address:
- Suzhou, China
- Editors:
- Barry Haddow, Tom Kocmi, Philipp Koehn, Christof Monz
- Venue:
- WMT
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 301–313
- Language:
- URL:
- https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.wmt-1.18/
- DOI:
- 10.18653/v1/2025.wmt-1.18
- Cite (ACL):
- Yasser Hamidullah, Shakib Yazdani, Cennet Oguz, Josef Van Genabith, and Cristina España-Bonet. 2025. SONAR-SLT: Multilingual Sign Language Translation via Language-Agnostic Sentence Embedding Supervision. In Proceedings of the Tenth Conference on Machine Translation, pages 301–313, Suzhou, China. Association for Computational Linguistics.
- Cite (Informal):
- SONAR-SLT: Multilingual Sign Language Translation via Language-Agnostic Sentence Embedding Supervision (Hamidullah et al., WMT 2025)
- PDF:
- https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.wmt-1.18.pdf