Speech processing apparatus and method and computer readable medium encoded with a program for recognizing input speech by performing searches based on a normalized current feature parameter

摘要

An apparatus, method, and storage medium for eliminating the influence of line characteristics in a real-time manner in order to raise recognition precision of input speech and to enable the speech to be recognized in a real-time manner, includes a device and step for obtaining, an estimate value of a long-time mean of a parameter from speech feature parameters which are sequentially inputted by using the speech feature parameters which have already been inputted, and a device and step for normalizing the speech feature parameter inputted at that time point by using the obtained estimate value. Each time the speech feature parameter is inputted, the latest estimate value is obtained by using the already inputted parameters including the inputted speech feature parameter, and the latest input speech feature parameter is normalized by using the updated estimate value. Since the reliability of the estimate value is higher as the number of speech feature parameters used when the estimate value is obtained is larger, the estimate value is normalized by adding a weight in accordance with the reliability.