JPhonABX: Japanese Phonological Discrimination Dataset for Moraic and Accentual Minimal Pairs

Yurie Koga, Shunsuke Kando, Yusuke Miyao


Abstract
Self-supervised speech models are known to encode phonological information, yet it remains underexplored whether they capture phonological properties characteristic of Japanese, such as mora and pitch accent. This paper introduces JPhonABX, a Japanese phonological discrimination dataset targeting moraic and accentual contrasts. It consists of 192,000 moraic and 98,000 accentual ABX test items, covering various types of contrasts such as those involving moraic nasal, geminate consonant, vowel length, and pitch accent. Our human evaluation by native Japanese speakers shows high discrimination accuracy and inter-rater agreement, validating the quality of the dataset. We further evaluate several self-supervised speech models and find that while almost all of them show no significant difference from humans in mora discrimination, they perform significantly worse in accent discrimination, and even models trained on Japanese fail to reach human-level performance.
Anthology ID:
2026.findings-emnlp.1072
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
22676–22695
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1072/
DOI:
10.18653/2026.findings-emnlp.1072
Bibkey:
Cite (ACL):
Yurie Koga, Shunsuke Kando, and Yusuke Miyao. 2026. JPhonABX: Japanese Phonological Discrimination Dataset for Moraic and Accentual Minimal Pairs. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 22676–22695, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
JPhonABX: Japanese Phonological Discrimination Dataset for Moraic and Accentual Minimal Pairs (Koga et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1072.pdf