Fine-Tashkeel at KSAA-2026: A Comprehensive Evaluation of Seq2Seq and Multimodal Approaches for Automatic Diacritization of Arabic Speech Dictation

Hassan Barmandah, Fatimah Emad Eldin, Omer Nacar, Wareef Alzubaidi


Abstract
This paper presents the Fine-Tashkeel system for Task 2 of the KSAA-2026 Shared Task on Automatic Diacritization of Speech Dictation. Diacritization of speech-derived Arabic text poses challenges due to dialectal variation, morphological ambiguity, and the absence of acoustic cues in text-only pipelines. Our approach treats diacritization as a character-level sequence-to-sequence task, mapping undiacritized text directly to its fully diacritized form. We evaluate 18 models spanning text-only, ASR-augmented, and fine-tuned configurations, finding that text-only Seq2Seq approaches outperform off-the-shelf multimodal models—a gap we attribute to task mismatch in generic ASR systems rather than an inherent audio limitation. Our best submission, using zero-shot inference without task-specific training, achieved a Diacritic Error Rate (DER) of 10.56%, Word Error Rate (WER) of 34.47%, and Sentence Error Rate (SER) of 79.88%, ranking 5th out of 7 teams. Per-nationality error analysis reveals significant dialectal variation (Egyptian 3.70% vs. Algerian 13.73% DER), and diagnostic analysis confirms that case endings and vowel ambiguity are the primary bottlenecks. Code and evaluation scripts are publicly available.
Anthology ID:
2026.osact-1.31
Volume:
The 7th Workshop on Open-Source Arabic Corpora and Processing Tools (OSACT7) with 5 Shared Tasks
Month:
May
Year:
2026
Address:
Palma, Mallorca (Spain)
Editors:
Hend Al-Khalifa, Mo El-Haj, Saad Ezzini
Venues:
OSACT | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
234–246
Language:
External URL:
https://lrec.elra.info/lrec2026-ws-osact-31
DOI:
10.63317/4rgtj4c7thyj
Bibkey:
Cite (ACL):
Hassan Barmandah, Fatimah Emad Eldin, Omer Nacar, and Wareef Alzubaidi. 2026. Fine-Tashkeel at KSAA-2026: A Comprehensive Evaluation of Seq2Seq and Multimodal Approaches for Automatic Diacritization of Arabic Speech Dictation. In The 7th Workshop on Open-Source Arabic Corpora and Processing Tools (OSACT7) with 5 Shared Tasks, pages 234–246, Palma, Mallorca (Spain). Association for Computational Linguistics.
Cite (Informal):
Fine-Tashkeel at KSAA-2026: A Comprehensive Evaluation of Seq2Seq and Multimodal Approaches for Automatic Diacritization of Arabic Speech Dictation (Barmandah et al., OSACT 2026)
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