9th Annual Conference of the International Speech Communication Association

Brisbane, Australia
September 22-26, 2008

Automatic-Type Calibration of Traditionally Derived Likelihood Ratios: Forensic Analysis of Australian English /o/ Formant Trajectories

Geoffrey Stewart Morrison (1), Yuko Kinoshita (2)

(1) Australian National University, Australia; (2) University of Canberra, Australia

A traditional-style phonetic-acoustic forensic-speaker-recognition 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 cross-validated 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.

Full Paper

Bibliographic reference.  Morrison, Geoffrey Stewart / Kinoshita, Yuko (2008): "Automatic-type calibration of traditionally derived likelihood ratios: forensic analysis of australian English /o/ formant trajectories", In INTERSPEECH-2008, 1501-1504.