TwinShift: Benchmarking Audio Deepfake Detection across Synthesizer and Speaker Shifts
Jiyoung Hong, Yoonseo Chung, Seungyeon Oh, Juntae Kim, Jiyoung Lee, Sookyung Kim, Hyunsoo Cho
TL;DR
Audio deepfake detectors currently fail to generalize to unseen synthesis methods and speakers. TwinShift introduces a dual-axis benchmark with six unseen synthesis systems and disjoint speakers to stress-test robustness, revealing major gaps where generator shifts dominate degradation and cross-environment transfer is highly asymmetric. Across detectors and environments, no single approach delivers universal resilience, and high-fidelity spoofs do not guarantee broad transfer, underscoring the need for holistic improvements in both data diversity and modeling. The benchmark provides a principled framework to guide development of ADD systems capable of withstanding evolving spoofing threats in real-world deployments.
Abstract
Audio deepfakes pose a growing threat, already exploited in fraud and misinformation. A key challenge is ensuring detectors remain robust to unseen synthesis methods and diverse speakers, since generation techniques evolve quickly. Despite strong benchmark results, current systems struggle to generalize to new conditions limiting real-world reliability. To address this, we introduce TWINSHIFT, a benchmark explicitly designed to evaluate detection robustness under strictly unseen conditions. Our benchmark is constructed from six different synthesis systems, each paired with disjoint sets of speakers, allowing for a rigorous assessment of how well detectors generalize when both the generative model and the speaker identity change. Through extensive experiments, we show that TWINSHIFT reveals important robustness gaps, uncover overlooked limitations, and provide principled guidance for developing ADD systems. The TWINSHIFT benchmark can be accessed at https://github.com/intheMeantime/TWINSHIFT.
