Phonological Abstraction and Exception Memorization in Noisy Tone Learning

Yi Yang, Yiming Wang, Jiahong Yuan


Abstract
Transformer-based speech models have recently been shown to perform well under impoverished and ambiguous supervision, a setting motivated by poverty-of-the-stimulus arguments, yet their learning dynamics remain unclear. In this work, we study this question with wav2vec2.0 on Mandarin tone classification, using 70 scale–noise configurations, capacity interventions, and perturbation probes to examine the dynamics of abstraction-consistent generalization and exception memorization, yielding representative regimes of Robust Generalization, Abrupt Transition, and High-noise Collapse. We find a consistent abstraction–exception trajectory: when phonological recovery is possible, the model first exhibits phonologically abstraction-consistent behavior and only later fits corrupted labels as empirical exceptions. Capacity analyses show that this trajectory is not merely a large-model artifact: it persists under truncated Transformer encoders, while acoustic rank compression modulates but does not selectively separate abstraction from exception memorization. Finally, acoustic perturbations show different local robustness: abstraction-consistent predictions remain stable under stronger waveform perturbations, whereas fitted exceptions behave as fragile local overrides on top of the broader abstraction-consistent behavior.
Anthology ID:
2026.findings-emnlp.1693
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:
36181–36199
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1693/
DOI:
Bibkey:
Cite (ACL):
Yi Yang, Yiming Wang, and Jiahong Yuan. 2026. Phonological Abstraction and Exception Memorization in Noisy Tone Learning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 36181–36199, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Phonological Abstraction and Exception Memorization in Noisy Tone Learning (Yang et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.1693.pdf