Forensic voice comparison using long-term acoustic measures of voice quality
Amanda Cardoso, Paul Foulkes, John Peter French, Amelia Gully, Philip Harrison, Vincent Hughes · White Rose Research Online (University of Leeds, The University of Sheffield, University of York) · 2019
Voice quality (VQ) is reported by forensic analysts to be a useful variable in voice comparison casework.Despite this, very little research has assessed empirically the efficacy of VQ as a speaker discriminant.This paper employs semi-automatic methods to test the performance of a forensic voice comparison system based on long-term acoustic measures of laryngeal VQ.Fundamental frequency, cepstral peak prominence, harmonics-to-noise ratios and a range of spectral tilt measures were extracted from vowel-only samples of studio, landline telephone, and mobile telephone recordings.Using likelihood ratio-based testing, the VQ features produced promising results.The high quality condition produced EERs as low as 5.8% and Cllrs as low as 0.26, although performance was degraded in the landline and mobile telephone conditions.When fused with a baseline MFCC system, results were mixed, with VQ improving performance only for some configurations of speakers.