WaveDetect: Robust Framework for Machine-Generated Text Detection via Wavelet Transform

Zhichen Liu, Kaitong Qin, Linhan He, Yang Xu


Abstract
As Large Language Models asymptotically approach human-level fluency in natural language generation, solely relying on surface-level semantic artifacts for detecting LLM-generated texts has become increasingly precarious. Existing detectors often falter when facing three critical challenges: adversarial perturbations, cross-domain shifts, and the rapid temporal evolution of the foundation model. To address these issues, we propose , a novel framework that reformulates text detection as a signal processing task within the time-frequency domain. Unlike previous methods that analyze static token probability distributions, models the generated output as a probability signal, upon which a differentiable Continuous Wavelet Transform is applied to convert them into learnable spectral representations. This process reveals the intrinsic “spectral fingerprints” in machine-generated texts–patterns that remain invisible in time domain. Comprehensive evaluations on three well-curated datasets (RAID, EvoBench, and Domain-Shift) show that our method achieves a new state-of-the-art. It not only achieves superior accuracy but also exhibits remarkable robustness against sophisticated attacks, generalization across out-of-distribution topics and unseen evolving LLMs. Our results validate the efficacy of spectral analysis as a promising paradigm for LLM-generated texts detection.
Anthology ID:
2026.findings-acl.424
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
8712–8727
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.424/
DOI:
Bibkey:
Cite (ACL):
Zhichen Liu, Kaitong Qin, Linhan He, and Yang Xu. 2026. WaveDetect: Robust Framework for Machine-Generated Text Detection via Wavelet Transform. In Findings of the Association for Computational Linguistics: ACL 2026, pages 8712–8727, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
WaveDetect: Robust Framework for Machine-Generated Text Detection via Wavelet Transform (Liu et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.424.pdf
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