Statistical models in forensic voice comparison

Abstract

This chapter describes a number of signal-processing and statistical-modeling techniques that are commonly used to calculate likelihood ratios in human-supervised automatic approaches to forensic voice comparison. Techniques described include mel frequency cepstral coefficients (MFCCs) feature extraction, Gaussian mixture model - universal background model (GMM-UBM) systems, i-vector - probabilistic linear discriminant analysis (i-vector PLDA) systems, deep neural network (DNN) based systems (including senone posterior i-vectors, bottleneck features, and embeddings / x-vectors), mismatch compensation, and score to likelihood ratio conversion (aka calibration). Empirical validation of forensic voice comparison systems is also covered. The aim of the chapter is to bridge the gap between general introductions to forensic voice comparison and the highly technical automatic speaker recognition literature from which the signal-processing and statistical-modeling techniques are mostly drawn. Knowledge of the likelihood ratio framework for the evaluation of forensic evidence is assumed. It is hoped that the material presented here will be of value to students of forensic voice comparison and to researchers interested in learning about statistical modeling techniques that could potentially also be applied to data from other branches of forensic science.

Divisions: Languages & Social Sciences > Aston Institute for Forensic Linguistics
Languages & Social Sciences
Additional Information: This is an Accepted Manuscript of a book chapter published by CRC Press in Handbook of Forensic Statistics on 3 Sept 2020, available online: https://www.crcpress.com/Handbook-of-Forensic-Statistics/Banks-Kafadar-Kaye-Tackett/p/book/9781138295407
ISBN: 9781138295407
Full Text Link: https://arxiv.o ... /abs/1912.13242
Related URLs: https://www.crc ... k/9781138295407 (Publisher URL)
PURE Output Type: Chapter (peer-reviewed)
Published Date: 2020-09-03
Accepted Date: 2019-02-23
Authors: Morrison, Geoffrey Stewart ( 0000-0001-8608-8207)
Enzinger, Ewald
Ramos, Daniel
González-Rodríguez, Joaquín
Lozano-Díez, Alicia

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Version: Accepted Version

Access Restriction: Restricted to Repository staff only until 3 March 2022.


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