Patent ID: 6735562
Filing Date: 2004-05-11
Classification: G10L

Abstract:
A method of estimating a confidence measure for a speech recognition system, the method comprising the steps of:receiving an input utterance; comparing the input utterance with a plurality of predetermined models of possible utterances to provide a plurality of scores indicating a degree of similarity between the input utterance and the plurality of predetermining models; determining a variance of a predetermined number of the plurality of scores; and normalizing the variance to provide a confidence measure for a likely recognition result for the in put utterance, wherein the confidence measure (CM) is calculated by: CM=1N&it;&Sum;i=1N&it;â€ƒ&it;(Si-Î¼Î¼)2where CM is the confidence measure, N is a predetermined number of N-Best scores, Si is the i-th best score, and &mgr; is the mean calculated by: Î¼=1N&it;&Sum;i=1N&it;â€ƒ&it;Si.