BSC’s Submission to the Instruction Following Track of IWSLT 2026

Oriol Pareras, Joan Llado, Pol Buitrago, Marc Casals-Salvador, Federico Costa, Cristina Espana-Bonet


Abstract
We present the Barcelona Supercomputing Center (BSC) submission to the Instruction Following (IF) track of IWSLT 2026, which evaluates unified spoken language systems capable of solving multiple tasks through natural language instructions. Our system consists of an end-to-end (E2E) architecture that combines a speech encoder with a translation-oriented Large Language Model. The model is trained on speech and text data, covering automatic speech recognition, translation, question answering, and instruction following. We investigate a Chain-of-Thought (CoT) generation strategy that explicitly decomposes tasks by producing an intermediate transcription before the final output, which enables effective reuse of text-only supervision and improves robustness across tasks. To further support generalization, we design diverse prompt formulations and align text-only and speech inputs under a shared inference pattern. Results on IWSLT 2025 evaluation data show that our approach achieves competitive and even state-of-the-art performance across tasks.
Anthology ID:
2026.iwslt-1.19
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:
171–182
Language:
URL:
https://aclanthology.org/2026.iwslt-1.19/
DOI:
Bibkey:
Cite (ACL):
Oriol Pareras, Joan Llado, Pol Buitrago, Marc Casals-Salvador, Federico Costa, and Cristina Espana-Bonet. 2026. BSC’s Submission to the Instruction Following Track of IWSLT 2026. In Proceedings of the 23rd International Conference on Spoken Language Translation (IWSLT 2026), pages 171–182, San Diego, USA (in-person and online). Association for Computational Linguistics.
Cite (Informal):
BSC’s Submission to the Instruction Following Track of IWSLT 2026 (Pareras et al., IWSLT 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.iwslt-1.19.pdf