SONIC-O1: A Real-World Benchmark for Evaluating Multimodal Large Language Models on Audio-Video Understanding

Ahmed Y. Radwan, Christos Emmanouilidis, Hina Tabassum, Deval Pandya, Shaina Raza


Abstract
Multimodal Large Language Models (MLLMs) are a major focus of recent AI research. However, most prior work focuses on static image understanding, while their ability to process audio–video data remains underexplored. This gap highlights the need for a high-quality benchmark to systematically evaluate MLLM performance in a real-world setting.

We introduce SONIC-O1, a comprehensive, fully human-verified benchmark of ≈60 hours (231 clips) spanning 13 real-world conversational domains with 4,958 annotations and perceived demographic metadata. SONIC-O1 evaluates three capabilities: open-ended summarization, multiple-choice question (MCQ) answering, and temporal localization with supporting rationales (reasoning). Across closed- and open-source models, we find that the MCQ accuracy shows the smallest gap between model families, under their recommended settings, the best closed-source model outperforms the best open-source model by 22.6% on temporal localization.

We further observe accuracy gaps of up to 21.4% on temporal localization across demographic groups, indicating diagnostic disparities in model behaviour. SONIC-O1 provides an open evaluation suite for temporally grounded and demographically informed multimodal understanding.

We release SONIC-O1 for reproducibility and research: Project Page: https://vectorinstitute.github.io/sonic-o1, Dataset: https://huggingface.co/datasets/vector-institute/sonic-o1 , Code Repository: https://github.com/VectorInstitute/sonic-o1.
Anthology ID:
2026.emnlp-main.767
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
17786–17825
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URL:
https://aclanthology.org/2026.emnlp-main.767/
DOI:
Bibkey:
Cite (ACL):
Ahmed Y. Radwan, Christos Emmanouilidis, Hina Tabassum, Deval Pandya, and Shaina Raza. 2026. SONIC-O1: A Real-World Benchmark for Evaluating Multimodal Large Language Models on Audio-Video Understanding. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 17786–17825, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
SONIC-O1: A Real-World Benchmark for Evaluating Multimodal Large Language Models on Audio-Video Understanding (Radwan et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.767.pdf