A Comparison of Differential Performance Metrics for the Evaluation of Automatic Speaker Verification Fairness
Oubaida Chouchane, Christoph Busch, Chiara Galdi, Nicholas Evans, Massimiliano Todisco
TL;DR
This paper addresses fairness in automatic speaker verification (ASV) by evaluating three candidate fairness metrics across multiple operating points. It compares FDR, IR, and GARBE, using five state-of-the-art ASV systems trained on VoxCeleb data and evaluated on a balanced, multi-national subset, following ISO/IEC DIS 19795-10 guidelines. The study finds that GARBE best satisfies the Functional Fairness Measure Criteria (FFMC), while FDR suffers from scale imbalances between FMR and FNMR differentials and IR is unbounded or incalculable in many cases, revealing a critical trade-off between fairness and verification performance. The work advocates fairness-by-design in ASV development and positions GARBE as a robust, interpretable metric for biometric fairness in practical deployments.
Abstract
When decisions are made and when personal data is treated by automated processes, there is an expectation of fairness -- that members of different demographic groups receive equitable treatment. This expectation applies to biometric systems such as automatic speaker verification (ASV). We present a comparison of three candidate fairness metrics and extend previous work performed for face recognition, by examining differential performance across a range of different ASV operating points. Results show that the Gini Aggregation Rate for Biometric Equitability (GARBE) is the only one which meets three functional fairness measure criteria. Furthermore, a comprehensive evaluation of the fairness and verification performance of five state-of-the-art ASV systems is also presented. Our findings reveal a nuanced trade-off between fairness and verification accuracy underscoring the complex interplay between system design, demographic inclusiveness, and verification reliability.
