1. A method for determining a set of distortion measures in a pattern recognition process where a sequence of feature vectors is formed from a digitized incoming signal to be recognized, said pattern recognition being based upon said set of distortion measures, comprising: comparing a first feature vector in said sequence with a first number of templates from a set of templates representing candidate patterns, based on said comparison, selecting a second number of templates from said template set, the second number being smaller than the first number, and comparing a second feature vector only with said selected templates.