The role of Voice Activity Detection in forensic speaker verification

Abstract

This paper presents an analysis of the role of Voice Activity Detection (VAD) algorithms in forensic speaker verification systems. Those systems often have to deal with noisy phone tappings, so the activity of the separation of speech and noise, performed by VAD algorithms, is crucial. In this work we evaluate the performance of 2 widespread VAD algorithms and the corresponding performance of the speaker verification systems, using 3 kinds of additive noise (CAR, FACTORY and OFFICE) and 3 values of Signal to Noise Ratio (SNR); we then analyze the error rates showing that using a single VAD algorithm often is not the best choice in this context, but instead the VAD algorithm should be dynamically chosen according to the conditions of the audio material.