Sabaa at NADI 2026 Subtask 1.1: Matching Annotation Conventions for Dialectal Arabic ASR

Mohamed Sabaa, Amr Sabaa


Abstract
This paper describes our submission to NADI 2026 Subtask 1.1, speech recognition for eight Arabic dialects under noisy conditions. Our system adapts whisper-large-v3-turbo with one low-rank adapter per dialect, decodes with tuned beam search, and applies a normalization step that matches the spelling conventions of the reference transcriptions rather than applying generic orthographic rules. We train only on the shared-task data, which places our results well below those of systems built with large external corpora, and we report our numbers with that constraint in mind. Country-average WER falls from 0.804 for the zero-shot backbone to 0.6053 on the test set. We also report three observations that shaped the system: per-dialect adapters outperform a jointly trained adapter on all eight dialects even when the joint model is trained for twice as long; replacing beam search with temperature sampling in order to produce diverse hypotheses for rescoring costs more accuracy than the rescoring recovers; and because the official scorer normalizes hypothesis and reference identically, generic character-level normalization cannot help, whereas learning each dialect’s annotation convention from the training transcriptions does.
Anthology ID:
2026.arabicnlp-sharedtasks.2
Volume:
Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Muhammad Abdul-Mageed, Tamer Elsayed, Houda Bouamor, Samhaa El-Beltagy, Hend Al-Khalifa, Ahmed Abdelali, AbdelRahim Elmadany, Abdellah El Mekki, Kareem Darwish, Sakhar Alkhereyf, Hamzah Luqman, Salam Khalifa, Samar Magdy, Zaid Alyafeai, Injy Hamed, Wajdi Zaghouani, Imed Zitouni
Venue:
ArabicNLP
SIG:
SIGARAB
Publisher:
Association for Computational Linguistics
Note:
Pages:
31–36
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.2/
DOI:
Bibkey:
Cite (ACL):
Mohamed Sabaa and Amr Sabaa. 2026. Sabaa at NADI 2026 Subtask 1.1: Matching Annotation Conventions for Dialectal Arabic ASR. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 31–36, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Sabaa at NADI 2026 Subtask 1.1: Matching Annotation Conventions for Dialectal Arabic ASR (Sabaa & Sabaa, ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.2.pdf