Explainable AI for Forensic Speech Authentication within Cognitive and Computational Neuroscience

Zhe Cheng¹Haitao Yang¹Yingzhuo Xiong¹Xuran Hu^2*

• ¹Hunan Police Academy, Changsha, China
• ²Xidian University School of Mechano-Electronic Engineering, Xi'an, China

The proliferation of deepfake technologies presents serious challenges for forensic speech authentication. We propose a deep learning framework combining Convolutional Neural Networks (CNNs) and Long Short-Term Memory (LSTM) networks to improve detection of manipulated audio. Leveraging the spectral feature extraction of CNNs and the temporal modeling of LSTMs, the model demonstrates superior accuracy and generalization across the ASVspoof2019 LA and WaveFake datasets. Linear Frequency Cepstral Coefficients (LFCCs) were employed as acoustic features and outperformed MFCC and GFCC representations. To enhance transparency and trustworthiness, explainable artificial intelligence (XAI) techniques, including Grad-CAM and SHAP, were applied, revealing that the model focuses on high-frequency artefacts and temporal inconsistencies. These interpretable analyses validate both the model's design and the forensic relevance of LFCC features. The proposed approach thus provides a robust, interpretable, and XAI-driven solution for forensic authentic detection.