Automatic-type calibration of traditionally derived likelihood ratios: forensic analysis of australian English /o/ formant trajectories

A traditional-style phonetic-acoustic forensic-speakerrecognition analysis was conducted on Australian English /o/ recordings. Different parametric curves were fitted to the formant trajectories of the vowel tokens, and cross-validated likelihood ratios were calculated using a single-stage generative multivariate kernel density formula. The outputs of different systems were compared using Cllr, a metric developed for automatic speaker recognition, and the crossvalidated likelihood ratios were calibrated using a procedure developed for automatic speaker recognition. Calibration ameliorated some likelihood-ratio results which had offered strong support for a contrary-to-fact hypothesis. Index Terms: forensic speaker recognition, calibration, formant trajectories

[1]  Niko Brümmer,et al.  Application-independent evaluation of speaker detection , 2006, Comput. Speech Lang..

[2]  S A Zahorian,et al.  Speaker normalization of static and dynamic vowel spectral features. , 1991, The Journal of the Acoustical Society of America.

[3]  S. Zahorian,et al.  Spectral-shape features versus formants as acoustic correlates for vowels. , 1993, The Journal of the Acoustical Society of America.

[4]  J. Goodman,et al.  CeKlotho opens a new road for investigation in worm aging , 2010, Aging.

[5]  Ian W. Evett,et al.  Commentary on A. P. A. Broeders (1999) ‘Some observations on the use of probability scales in forensic identification’, Forensic Linguistics 6(2): 228–41 , 2000 .

[6]  Colin Aitken,et al.  Evaluation of trace evidence in the form of multivariate data , 2004 .

[7]  Terrance M. Nearey,et al.  Evaluation of a strategy for automatic formant tracking , 2002 .

[8]  Javier Ortega-Garcia,et al.  Robust estimation, interpretation and assessment of likelihood ratios in forensic speaker recognition , 2006, Comput. Speech Lang..

[9]  Doroteo Torre Toledano,et al.  Emulating DNA: Rigorous Quantification of Evidential Weight in Transparent and Testable Forensic Speaker Recognition , 2007, IEEE Transactions on Audio, Speech, and Language Processing.

[10]  A. Broeders,et al.  Some observations on the use of probability scales in forensic identification , 1999 .

[11]  Phil Rose.  Accounting for Correlation in Linguistic-Acoustic Likelihood Ratio-based Forensic Speaker Discrimination , 2006, 2006 IEEE Odyssey - The Speaker and Language Recognition Workshop.

[12]  John E. Markel,et al.  Linear Prediction of Speech , 1976, Communication and Cybernetics.