A future for universal grapheme-phoneme transduction modeling with neuralized finite-state transducers

Chu-Cheng Lin Lin


Abstract
We propose a universal grapheme-phoneme transduction model using neuralized finite-state transducers. Many computational models of grapheme-phoneme transduction nowadays are based on the (autoregressive) sequence-to-sequence string transduction paradigm. While such models have achieved state-of-the-art performance, they suffer from theoretical limitations of autoregressive models. On the other hand, neuralized finite-state transducers (NFSTs) have shown promising results on various string transduction tasks. NFSTs can be seen as a generalization of weighted finite-state transducers (WFSTs), and can be seen as pairs of a featurized finite-state machine (‘marked finite-state transducer’ or MFST in NFST terminology), and a string scoring function. Instead of taking a product of local contextual feature weights on FST arcs, NFSTs can employ arbitrary scoring functions to weight global contextual features of a string transduction, and therefore break the Markov property. Furthermore, NFSTs can be formally shown to be more expressive than (autoregressive) seq2seq models. Empirically, joint grapheme-phoneme transduction NFSTs have consistently outperformed vanilla seq2seq models on grapheme-tophoneme and phoneme-to-grapheme transduction tasks for English. Furthermore, they provide interpretable aligned string transductions, thanks to their finite-state machine component. In this talk, we propose a multilingual extension of the joint grapheme-phoneme NFST. We achieve this goal by modeling typological and phylogenetic features of languages and scripts as optional latent variables using a finite-state machine. The result is a versatile graphemephoneme transduction model: in addition to standard monolingual and multilingual transduction, the proposed multilingual NFST can also be used in various controlled generation scenarios, such as phoneme-to-grapheme transduction of an unseen language-script pair. We also plan to release an NFST software package.
Anthology ID:
2023.sigmorphon-1.30
Volume:
Proceedings of the 20th SIGMORPHON workshop on Computational Research in Phonetics, Phonology, and Morphology
Month:
July
Year:
2023
Address:
Toronto, Canada
Editors:
Garrett Nicolai, Eleanor Chodroff, Frederic Mailhot, Çağrı Çöltekin
Venue:
SIGMORPHON
SIG:
SIGMORPHON
Publisher:
Association for Computational Linguistics
Note:
Pages:
249–249
Language:
URL:
https://aclanthology.org/2023.sigmorphon-1.30
DOI:
10.18653/v1/2023.sigmorphon-1.30
Bibkey:
Cite (ACL):
Chu-Cheng Lin Lin. 2023. A future for universal grapheme-phoneme transduction modeling with neuralized finite-state transducers. In Proceedings of the 20th SIGMORPHON workshop on Computational Research in Phonetics, Phonology, and Morphology, pages 249–249, Toronto, Canada. Association for Computational Linguistics.
Cite (Informal):
A future for universal grapheme-phoneme transduction modeling with neuralized finite-state transducers (Lin, SIGMORPHON 2023)
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PDF:
https://aclanthology.org/2023.sigmorphon-1.30.pdf