Abstract
Grapheme-to-phoneme (G2P) conversion turns raw text into its phonemic form and is an essential part of both text-to-speech (TTS) and automatic speech recognition (ASR) systems. It is required to be fast, stable and context-aware. For unsegmented languages such as Japanese, G2P additionally couples word segmentation with highly context-dependent polyphone disambiguation, and the scarcity of accurately annotated data remains a bottleneck. In this paper, we present a context-aware, segmentation-agnostic neural G2P framework that models the joint segmentation-and-reading hypothesis space, scoring paths of a discriminative conditional random field (CRF) over a dictionary-derived word lattice. To tackle data scarcity, we utilize large language models (LLMs) to generate more than 2 million sentences. Experimental results demonstrate that our method substantially outperforms conventional morphological analyzer-based methods and neural sequence models. On the Joyo-Kanji-Yomi benchmark, our method reaches 99.62% target word reading accuracy, 0.32% target word phoneme error rate (PER) and 0.14% sentence PER.
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Publication details
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- Open access
- Green open access
Cite this article
APA 7
Hu, R., Zhan, Z., & Lin, X. (2026). Dictionary-Constrained Grapheme-to-Phoneme for Unsegmented Languages from LLM-Annotated Data. https://omanscience.com/en/articles/dictionary-constrained-grapheme-to-phoneme-for-unsegmented-languages-from-llm-annotated-data
MLA 9
Hu, Rui, et al. "Dictionary-Constrained Grapheme-to-Phoneme for Unsegmented Languages from LLM-Annotated Data." https://omanscience.com/en/articles/dictionary-constrained-grapheme-to-phoneme-for-unsegmented-languages-from-llm-annotated-data.
Chicago (author–date)
Hu, Rui, Zhenpeng Zhan, and Xiaolong Lin. 2026. "Dictionary-Constrained Grapheme-to-Phoneme for Unsegmented Languages from LLM-Annotated Data." https://omanscience.com/en/articles/dictionary-constrained-grapheme-to-phoneme-for-unsegmented-languages-from-llm-annotated-data.
Harvard
Hu, R., Zhan, Z. and Lin, X. (2026) 'Dictionary-Constrained Grapheme-to-Phoneme for Unsegmented Languages from LLM-Annotated Data', Available at: https://omanscience.com/en/articles/dictionary-constrained-grapheme-to-phoneme-for-unsegmented-languages-from-llm-annotated-data.
Vancouver
Hu R, Zhan Z, Lin X. Dictionary-Constrained Grapheme-to-Phoneme for Unsegmented Languages from LLM-Annotated Data. https://omanscience.com/en/articles/dictionary-constrained-grapheme-to-phoneme-for-unsegmented-languages-from-llm-annotated-data
IEEE
R. Hu, Z. Zhan, and X. Lin, "Dictionary-Constrained Grapheme-to-Phoneme for Unsegmented Languages from LLM-Annotated Data," https://omanscience.com/en/articles/dictionary-constrained-grapheme-to-phoneme-for-unsegmented-languages-from-llm-annotated-data.