Speech recognition method and apparatus thereof

Abstract

A speech recognition method and apparatus in which a plurality of time-sequential acoustic parameters are derived from a segmented input speech signal and are used to form a first trajectory that is time normalized. The time-normalized trajectory is sampled at predetermined lengths therealong and the sampling results used to form a new time-normalized trajectory with equally spaced points ('dots' on the graph), which is compared with a plurality of previously registered trajectories until a match is found between the new time-normalized trajectory and one of the registered trajectories, at which time an indication of the results of the matching is produced. A silence acoustic parameter can also be added to the time-sequential acoustic parameters so that the time-normalized trajectory can start and end from a point of silence. In addition, the length of the first trajectory formed from the acoustic parameters derived from the segmented speech signals is determined and used in the matching operation with the registered trajectories, so that the lengths of the trajectories as well as the distances between the formed trajectory and the stored trajectory are also taken into account to increase the recognition ratio.