NaijaS2ST: A Multi-Accent Benchmark for Speech-to-Speech Translation in Low-Resource Nigerian Languages

Marie Maltais, Yejin Jeon, Min Ma, Shamsuddeen Hassan Muhammad, Idris Abdulmumin, Maryam Ibrahim Mukhtar, Daud Abolade, Okepefi Joel Monday, Johnson Sewedo Okepefi, David Ifeoluwa Adelani


Abstract
Speech translation for low-resource languages is constrained by the scarcity of high-quality parallel speech data, which is particularly pronounced in African linguistic contexts. To address this, we introduce , a parallel speech translation dataset covering Igbo, Hausa, , and Nigerian Pidgin paired with English. The dataset contains more than 40 hours of speech per language and includes several speaker and accent variations to reflect realistic settings. Using NaijaS2ST, we benchmark cascaded, end-to-end (E2E), and AudioLLM-based approaches across bidirectional translation directions (XX↔English). Our results show that few-shot audio LLMs are more effective than cascaded and E2E methods finetuned for speech-to-text translation. For speech-to-speech translation, however, cascaded and audio LLM paradigms perform comparatively, highlighting the need for stronger task-specific models. offers a strong foundation towards advancing research on low-resource multilingual speech translation. We open source the dataset here: [NaijaS2ST Huggingface Dataset](https://huggingface.co/datasets/McGill-NLP/NaijaS2ST); and the code here: [NaijaS2ST Code](https://github.com/McGill-NLP/naijas2st).
Anthology ID:
2026.emnlp-main.665
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
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
15311–15334
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URL:
https://aclanthology.org/2026.emnlp-main.665/
DOI:
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Cite (ACL):
Marie Maltais, Yejin Jeon, Min Ma, Shamsuddeen Hassan Muhammad, Idris Abdulmumin, Maryam Ibrahim Mukhtar, Daud Abolade, Okepefi Joel Monday, Johnson Sewedo Okepefi, and David Ifeoluwa Adelani. 2026. NaijaS2ST: A Multi-Accent Benchmark for Speech-to-Speech Translation in Low-Resource Nigerian Languages. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 15311–15334, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
NaijaS2ST: A Multi-Accent Benchmark for Speech-to-Speech Translation in Low-Resource Nigerian Languages (Maltais et al., EMNLP 2026)
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https://aclanthology.org/2026.emnlp-main.665.pdf