We propose an analogy to eye witness line-up in order to compute calibrated likelihood ratios for speaker recognition, by including the target model in an identification trial with a cohort of foils. Expressions for the likelihood ratio as a function of cohort size, identification rank and system ROC performance are derived, and some properties of the likelihood ratio function are discussed. The line-up procedure is used as a method to calibrate recognition scores. Using NIST SRE 2010, we find calibration loss comparable to linear calibration (FoCal), while the proposed method gives improved discrimination.
Bibliographic reference. Leeuwen, David A. van / Brümmer, Niko (2011): "A speaker line-up for the likelihood ratio", In INTERSPEECH-2011, 501-504.