MLLP-VRAIN UPV System for the IWSLT 2026 Simultaneous Speech Translation Task
Jorge Iranzo-Sánchez, Gerard Mas-Mollà, Adrià Gimenez, Jorge Civera Saiz, Albert Sanchis, Alfons Juan
Abstract
This work describes the participation of the MLLP-VRAIN research group in the shared task of the IWSLT 2026 Simultaneous Speech Translation track. Our submission utilizes the recently released Parakeet and Qwen 3.5 models to create a robust, cascaded solution for long-form SimulST through the use of adaptive black-box policies. We explore relaxations of these policies to achieve better quality-latency trade-offs. Compared to last year, we participate on all language directions. In addition to this, for the En→De, It, Zh directions we also participate in this year’s new context track employing a combination of ASR word-boosting and a RAG mechanism of offline pre-translated exemplars to guide generation and enrich our system with domain-specific context. Finally, we provide a detailed latency analysis of our system. Compared to last year, results on the MCIF En→De test set shows a substantial quality improvement of +5.82 XCOMET-XL. Our context track processing further improves performance by +1.03.- Anthology ID:
- 2026.iwslt-1.24
- 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:
- 212–226
- Language:
- URL:
- https://preview.aclanthology.org/bulk-corrections-2026-07-02/2026.iwslt-1.24/
- DOI:
- 10.18653/v1/2026.iwslt-1.24
- Cite (ACL):
- Jorge Iranzo-Sánchez, Gerard Mas-Mollà, Adrià Gimenez, Jorge Civera Saiz, Albert Sanchis, and Alfons Juan. 2026. MLLP-VRAIN UPV System for the IWSLT 2026 Simultaneous Speech Translation Task. In Proceedings of the 23rd International Conference on Spoken Language Translation (IWSLT 2026), pages 212–226, San Diego, USA (in-person and online). Association for Computational Linguistics.
- Cite (Informal):
- MLLP-VRAIN UPV System for the IWSLT 2026 Simultaneous Speech Translation Task (Iranzo-Sánchez et al., IWSLT 2026)
- PDF:
- https://preview.aclanthology.org/bulk-corrections-2026-07-02/2026.iwslt-1.24.pdf