11. A method for identifying an unknown speech segment in a continuous speech signal as one of a plurality of identified speech segments according to claim 10 wherein the unknown speech segment comprises an unknown spoken digit in a string of spoken digits and said identified speech segments comprise prescribed identified spoken digits.
10. A method for identifying an unknown speech segment in a continuous speech signal as one of a plurality of identified speech segments comprising the steps of generating a set of reference signals for each identified speech segment representative of the mean value m.sub.iq and variances S.sub.iq of the linear prediction characteristics of the average voiced intervals of said identified speech segment responsive to repetitions of strings of said identified speech segments where i = 1, 2, . . . , Nv are the frames of the average voiced intervals and q = 1, 2, . . . , Q is the identity of the identified speech segment; generating a set of test signals a(n).sub.i representative of the linear prediction coefficients of the voiced intervals of said unknown speech segment where n = 1, 2, . . . , p is the order of the coefficients and a signal R.sub.i representative of the autocorrelation coefficients of the voiced intervals of the unknown speech segment where i = 1, 2, . . . , Nv; determining the correspondence between said test signals and each identified speech segment reference signal comprising time aligning said unknown speech segment voiced interval test signals to the average voiced intervals of said identified speech segment to form a set of Nv test signals a.sub.i.sup.' corresponding to the Nv test signals a(n).sub.i jointly responsive to said aligned test voiced interval signals a.sub.i.sup.' and said identified speech segment voiced interval reference signals m.sub.iq, producing a signal ##EQU18## representative of the correspondence between said aligned voiced interval test signals a.sub.i.sup.' and said identified speech segment average voiced interval reference signals m.sub.iq ; selecting and storing the identity of the identified speech segment having the minimum D.sub.1q signal; producing a signal classifying the beginning frame of said unknown speech segment as one of voiced, unvoiced and silence; jointly responsive to said classifying signal and the identity of the unknown speech segment having the minimum D.sub.1q signal, generating a first signal when said classifying signal is consistent with said minimum D.sub.1q signal identity and a second signal when said classifying signal is inconsistent with said minimum D.sub.1q signal identity: identifying said unknown speech segment as said minimum D.sub.1q correspondence signal identity responsive to said first signal; responsive to said second signal, forming a ##EQU19## correspondence signal for each identified speech segment; and responsive to the D.sub.2q correspondence signals for the plurality of identified speech segments, selecting the identity of the identified speech segment having the minimum D.sub.2q correspondence signal as the identity of the unknown speech segment.