Abstract

Cross-linguistic effects are a central topic in bilingual first-language acquisition. Artificial learners can help investigate L1-L2 interactions by enabling controlled comparisons across language combinations and learning conditions. Recent work explores this direction by training bilingual language models under developmentally plausible constraints. However, human and model learners still diverge in fundamental ways, with one major difference being input modality: children learn primarily from spoken input, whereas language models are typically trained on orthographic text. To reduce this gap, researchers have trained models on phonemic representations of speech. In this work, we combine these research directions to train bilingual BabyLMs with phonemic input. We keep English fixed as the L2 and vary the L1 across German, Swedish, Persian, and Basque, selected to represent contrasting combinations of syntactic and phoneme-inventory distance from English. Our results show stronger L1-related variation in grammatical learning trajectories under phonemic than orthographic input, while early lexical differences align with phoneme-inventory similarity.

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Publication details

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Open access
Green open access

Cite this article

APA 7

Theodoropoulos, N., Lymperaiou, M., & Filandrianos, G. (2026). Cross-Linguistic Effects in Bilingual Phoneme BabyLMs. https://omanscience.com/en/articles/cross-linguistic-effects-in-bilingual-phoneme-babylms

MLA 9

Theodoropoulos, Nikitas, et al. "Cross-Linguistic Effects in Bilingual Phoneme BabyLMs." https://omanscience.com/en/articles/cross-linguistic-effects-in-bilingual-phoneme-babylms.

Chicago (author–date)

Theodoropoulos, Nikitas, Maria Lymperaiou, and Giorgos Filandrianos. 2026. "Cross-Linguistic Effects in Bilingual Phoneme BabyLMs." https://omanscience.com/en/articles/cross-linguistic-effects-in-bilingual-phoneme-babylms.

Harvard

Theodoropoulos, N., Lymperaiou, M. and Filandrianos, G. (2026) 'Cross-Linguistic Effects in Bilingual Phoneme BabyLMs', Available at: https://omanscience.com/en/articles/cross-linguistic-effects-in-bilingual-phoneme-babylms.

Vancouver

Theodoropoulos N, Lymperaiou M, Filandrianos G. Cross-Linguistic Effects in Bilingual Phoneme BabyLMs. https://omanscience.com/en/articles/cross-linguistic-effects-in-bilingual-phoneme-babylms

IEEE

N. Theodoropoulos, M. Lymperaiou, and G. Filandrianos, "Cross-Linguistic Effects in Bilingual Phoneme BabyLMs," https://omanscience.com/en/articles/cross-linguistic-effects-in-bilingual-phoneme-babylms.