TY - CHAP

T1 - Statistical models in forensic voice comparison

AU - Morrison, Geoffrey Stewart

AU - Enzinger, Ewald

AU - Ramos, Daniel

AU - González-Rodríguez, Joaquín

AU - Lozano-Díez, Alicia

N1 - This is an Accepted Manuscript of a book chapter published by CRC Press in Handbook of Forensic Statistics on 28 Sept 2020, available online: https://www.crcpress.com/Handbook-of-Forensic-Statistics/Banks-Kafadar-Kaye-Tackett/p/book/9781138295407

PY - 2020/9/28

Y1 - 2020/9/28

N2 - 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.

AB - 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.

UR - https://www.crcpress.com/Handbook-of-Forensic-Statistics/Banks-Kafadar-Kaye-Tackett/p/book/9781138295407

M3 - Chapter (peer-reviewed)

SN - 9781138295407

SP - 451

EP - 497

BT - Handbook of Forensic Statistics

A2 - Banks, D.L.

A2 - Kafadar, K.

A2 - Kaye, D.H.

A2 - Tackett, M.

PB - CRC Press

ER -