On calibration of language recognition scores

Recent publications have examined the topic of calibration of confidence scores in the field of (binary-hypothesis) speaker detection. We extend this topic to the case of multiple-hypothesis language recognition. We analyze the structure of multiple-hypothesis recognition problems to show that any such problem subsumes a multitude of derived sub-problems and that therefore the calibration of all of these problems are interrelated. We propose a simple global calibration metric that can be generally applied to a multiple-hypothesis problem and then demonstrate experimentally on some NIST-LRE-´05 data how this relates to the calibration of some of the derived binary-hypotheses sub-problems