CATENG Submission for the IWSLT 2026: Dialectal and Low-resource Speech Translation Task

Rodolfo Joel Zevallos, Marc Casals, John E. Ortega, Fabrício Carraro, Pol Buitrago, Guillermo Cámbara


Abstract
We present the CATENG systems submitted to the IWSLT 2026 Dialectal and Low-Resource Speech Translation shared task for the Catalan–English (CA–EN) pair. Although Catalan is not strictly low-resource, its dialectal diversity and relative under-representation in speech technology make it a challenging setting. We evaluate three unconstrained systems: two cascaded approaches combining ASR and MT, and one end-to-end model. Our primary system uses a Mamba-based ASR (ConMamba) with a fine-tuned NLLB-200 MT model, while a contrastive system replaces the ASR with Whisper-v3; we also evaluate an end-to-end SpeechT5 model with data augmentation. Experiments are conducted on the IWSLT 2026 Catalan dataset (15 hours), complemented with large-scale parallel text. Results show that cascaded systems outperform end-to-end ST, with Whisper-v3 + NLLB achieving 44.7 BLEU and 65.1 chrF. We find that performance is primarily constrained by ASR quality rather than MT capacity, and that Mamba-based ASR models provide competitive results, highlighting the importance of robust speech representations and dialectal coverage for Catalan–English speech translation.
Anthology ID:
2026.iwslt-1.18
Volume:
Proceedings of the 23rd International Conference on Spoken Language Translation (IWSLT 2026)
Month:
July
Year:
2026
Address:
San Diego, USA (in-person and online)
Editors:
Elizabeth Salesky, Antonios Anastasopoulos, Matteo Negri, Marcello Federico
Venues:
IWSLT | WS
SIG:
SIGSLT
Publisher:
Association for Computational Linguistics
Note:
Pages:
164–170
Language:
URL:
https://aclanthology.org/2026.iwslt-1.18/
DOI:
Bibkey:
Cite (ACL):
Rodolfo Joel Zevallos, Marc Casals, John E. Ortega, Fabrício Carraro, Pol Buitrago, and Guillermo Cámbara. 2026. CATENG Submission for the IWSLT 2026: Dialectal and Low-resource Speech Translation Task. In Proceedings of the 23rd International Conference on Spoken Language Translation (IWSLT 2026), pages 164–170, San Diego, USA (in-person and online). Association for Computational Linguistics.
Cite (Informal):
CATENG Submission for the IWSLT 2026: Dialectal and Low-resource Speech Translation Task (Zevallos et al., IWSLT 2026)
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PDF:
https://aclanthology.org/2026.iwslt-1.18.pdf