Effects of emphasizing transitional or stationary parts of the speech signal in a discrete utterance recognition system

A dynamic programming pattern matching isolated word recognition system has been modified in order to emphasize the transient parts of speech in the similarity measure. The technique is to weight the word distances with a normalized spectral change function. A small positive effect is measured. Emphasizing the stationary parts is shown to substantially decrease the performance. Adding the time derivative of the speech parameters to the word patterns improves performance significantly. This is probably a consequence of an improvement in the description of the transient segments.