English

On the Difficulty of Token-Level Modeling of Dysfluency and Fluency Shaping Artifacts

Audio and Speech Processing 2025-12-03 v1 Artificial Intelligence Computation and Language Machine Learning

Abstract

Automatic transcription of stuttered speech remains a challenge, even for modern end-to-end (E2E) automatic speech recognition (ASR) frameworks. Dysfluencies and fluency-shaping artifacts are often overlooked, resulting in non-verbatim transcriptions with limited clinical and research value. We propose a parameter-efficient adaptation method to decode dysfluencies and fluency modifications as special tokens within transcriptions, evaluated on simulated (LibriStutter, English) and natural (KSoF, German) stuttered speech datasets. To mitigate ASR performance disparities and bias towards English, we introduce a multi-step fine-tuning strategy with language-adaptive pretraining. Tokenization analysis further highlights the tokenizer's English-centric bias, which poses challenges for improving performance on German data. Our findings demonstrate the effectiveness of lightweight adaptation techniques for dysfluency-aware ASR while exposing key limitations in multilingual E2E systems.

Keywords

Cite

@article{arxiv.2512.02027,
  title  = {On the Difficulty of Token-Level Modeling of Dysfluency and Fluency Shaping Artifacts},
  author = {Kashaf Gulzar and Dominik Wagner and Sebastian P. Bayerl and Florian Hönig and Tobias Bocklet and Korbinian Riedhammer},
  journal= {arXiv preprint arXiv:2512.02027},
  year   = {2025}
}

Comments

6 pages, 1 figure. Accepted to ASRU 2025. This is the arXiv preprint of the accepted paper

R2 v1 2026-07-01T08:04:21.635Z