Abjad AI at NADI 2026 shared task: Overcoming Data Scarcity in Arabic Speech Processing through Augmentation

Hatim Alhumid, Naif Alharthi, Elaf S. Alsaedi, Faris Alasmary, Ahmad Ghannam, Anas Adel Salamah, Shouq Sadah, Lahouari Ghouti


Abstract
We describe our submission to three NADI 2026 subtasks: Tunisian Arabic–French–English code-switched ASR (Task 1.3), dialectal Arabic speech translation, and 20-way Arabic dialect identification (ADI). For code-switched ASR, we finetune a 2B-parameter FastConformer encoder-decoder with synthetic Tunisian speech, cross-lingual data, waveform augmentation, and checkpoint averaging, achieving 14.12% WER and ranking first overall. For speech translation, finetuning Whisper Large-v3 yields strong in-domain results but poor generalization (BLEU 5.8 on blind test), illustrating overfitting under limited data. For ADI, a classifier on frozen pretrained ASR representations outperforms full/partial finetuning, reaching 42% accuracy across 20 dialects. We highlight synthetic augmentation, checkpoint averaging, and encoder freezing as effective low-resource strategies.
Anthology ID:
2026.arabicnlp-sharedtasks.4
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:
47–52
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.4/
DOI:
Bibkey:
Cite (ACL):
Hatim Alhumid, Naif Alharthi, Elaf S. Alsaedi, Faris Alasmary, Ahmad Ghannam, Anas Adel Salamah, Shouq Sadah, and Lahouari Ghouti. 2026. Abjad AI at NADI 2026 shared task: Overcoming Data Scarcity in Arabic Speech Processing through Augmentation. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 47–52, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Abjad AI at NADI 2026 shared task: Overcoming Data Scarcity in Arabic Speech Processing through Augmentation (Alhumid et al., ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.4.pdf