XSQ-AST: An Explainable Audio Spectrogram Transformer Framework for Localising Synthetic Speech Artifacts

arXiv:2609.24770 · eess.AS, cs.LG, cs.SD, eess.SP · Submitted 2026-09-21 · Read on arXiv

eess.AS, cs.LG, cs.SD, eess.SP

Submitted: 2026-09-21

Updated: 2026-09-21

Comments: Submitted to IEEE ICASSP 2027

Code: https://github.com/luca-resti/synth-speech-eval

License: http://creativecommons.org/licenses/by/4.0/

The gist: Localising artifacts in synthetic speech remains challenging, as most evaluation methods yield only global quality scores.

Terminology

Abstract

Localising artifacts in synthetic speech remains challenging, as most evaluation methods yield only global quality scores. This paper presents XSQ-AST, a framework that combines the SQ-AST speech quality model with WhisperX phoneme alignment and multiple saliency methods to produce temporally localised artifact diagnostics without model retraining. Saliency maps are projected onto continuous distributions via kernel density estimation and onto phoneme boundaries via phoneme-discretised saliency maps. A 40-participant listening test validated the framework across five perceptual dimensions. Attention Rollout, Attention Flow and an adapted GradCAM produced temporal distributions that correlated with listener highlights, with different methods best suited to different artifact types. An AUC-ROC analysis confirmed discrimination above chance.

Sources

Related papers