Exposing Synthetic Speech: Model Attribution and Detection of AI-generated Speech via Audio Fingerprints
It addresses security risks like impersonation and misinformation by providing a practical tool for digital forensics, though it is incremental as it builds on existing fingerprinting ideas.
This work tackles the threat of malicious use of AI-generated speech by introducing a training-free approach for detecting synthetic speech and attributing it to source models, achieving AUROC scores over 99% in most scenarios.
As speech generation technologies continue to advance in quality and accessibility, the risk of malicious use cases, including impersonation, misinformation, and spoofing, increases rapidly. This work addresses this threat by introducing a simple, training-free, yet effective approach for detecting AI-generated speech and attributing it to its source model. Specifically, we tackle three key tasks: (1) single-model attribution in an open-world setting, where the goal is to determine whether a given audio sample was generated by a specific target neural speech synthesis system (with access only to data from that system); (2) multi-model attribution in a closed-world setting, where the objective is to identify the generating system from a known pool of candidates; and last but not least (3) detection of synthetic versus real speech. Our approach leverages standardized average residuals-the difference between an input audio signal and its filtered version using either a low-pass filter or the EnCodec audio autoencoder. We demonstrate that these residuals consistently capture artifacts introduced by diverse speech synthesis systems, serving as distinctive, model-agnostic fingerprints for attribution. Across extensive experiments, our approach achieves AUROC scores exceeding 99% in most scenarios, evaluated on augmented benchmark datasets that pair real speech with synthetic audio generated by multiple synthesis systems. In addition, our robustness analysis underscores the method's ability to maintain high performance even in the presence of moderate additive noise. Due to its simplicity, efficiency, and strong generalization across speech synthesis systems and languages, this technique offers a practical tool for digital forensics and security applications.