375 the utterance is rejected otherwise if either the score value is greater than the change in score value plus 250 or the change in score value is less than 28 an n best algorithm is applied to the utterance otherwise the utterance is accepted in the embodiment described with reference to fig2 two dimensions are used for the linear discriminative analysis the dimension u201c score u201d represents the distance between a given utterance and a given vr template as derived from the outputs of multiple bandpass filters not shown the dimension u201c change in score u201d represents the difference between the lowest score i e the closest matched score and the next lowest score i e the score for the next closest matched utterance in another embodiment the dimension u201c score u201d represents the distance between a given utterance and a given vr template as derived from the cepstral coefficients of the utterance in another embodiment the dimension u201c score u201d represents the distance between a given utterance and a given vr template as derived from the linear predictive coding lpc coefficients of the utterance techniques for deriving the lpc coefficients and the cepstral coefficients of an utterance are described in the aforementioned u s pat no 5 414 796 in alternate embodiments the linear discriminative analysis is not restricted to two dimensions accordingly a first score based upon bandpass filter outputs a second score based upon cepstral.