Harder or Different? Understanding Generalization of Audio Deepfake Detection
Authors: Nicolas M. Müller, Nicholas Evans, Hemlata Tak, Philip Sperl, Konstantin Böttinger
Published: 2024-06-05 10:33:15+00:00
AI Summary
This research investigates the generalization problem in audio deepfake detection, determining whether poor performance on unseen deepfakes is due to increased difficulty ('hardness') or fundamental differences ('difference') between deepfake generation methods. The study finds that performance gaps are primarily attributed to 'difference', implying that simply increasing model capacity is insufficient for robust generalization.
Abstract
Recent research has highlighted a key issue in speech deepfake detection: models trained on one set of deepfakes perform poorly on others. The question arises: is this due to the continuously improving quality of Text-to-Speech (TTS) models, i.e., are newer DeepFakes just 'harder' to detect? Or, is it because deepfakes generated with one model are fundamentally different to those generated using another model? We answer this question by decomposing the performance gap between in-domain and out-of-domain test data into 'hardness' and 'difference' components. Experiments performed using ASVspoof databases indicate that the hardness component is practically negligible, with the performance gap being attributed primarily to the difference component. This has direct implications for real-world deepfake detection, highlighting that merely increasing model capacity, the currently-dominant research trend, may not effectively address the generalization challenge.