Detector-Guided Vocoder Training for Adversarial Text-to-Speech Synthesis

In this paper, we propose a novel Text-to-Speech (TTS) framework designed to perform adversarial attacks against speech deepfake detection systems. Given a TTS model and a detector capable of classifying its outputs as synthetic, our approach fine-tunes the vocoder by integrating the detector into the TTS training loop. Unlike traditional adversarial methods that rely on post-hoc perturbations or external noise injection, our approach enables the generation of synthetic speech that is intrinsically adversarial, capable of lowering the target detector's reliability without requiring additional post-processing steps. We evaluate the framework in both white-box and black-box settings, showing its effectiveness against known and unseen detectors. We also propose a multi-detector strategy that allows the system to simultaneously learn to deceive multiple detectors, showcasing the scalability of the method. Experimental results confirm the efficacy of our approach, which has the potential to impact forensic security and detection countermeasures. At the same time, subjective listening tests reveal that the proposed method also enhances synthesized speech quality.