5. A speech recognizer for identifying an unknown spoken digit in a continuous string of spoken digits comprising means responsive to repetitions of identified digit strings by different speakers for generating a set of reference signals for each identified digit representative of the mean values m.sub.iq of the linear prediction coefficients of the average voiced interval of said identified digit and the covariance S.sub.iq of said linear prediction coefficients where i = 1, 2, . . . , Nv is the i.sup.th frame of the identified digit average voiced interval of Nv frames and q = 1, 2, . . . , Q is the identity of said identified spoken digit, means for partitioning said continuous string of spoken digits including said unknown spoken digit into its component spoken digits. means responsive to said partitioned unknown spoken digit in said string of spoken digits for generating a set of test signals a(n).sub.i representative of the linear prediction coefficients of the unknown digit voiced interval where n = 1, 2, . . . , p is the order of the coefficient and a signal R.sub.i representative of the autocorrelation coefficients of said unknown digit where i = 1, 2, . . . , Nv is the i.sup.th frame of the unknown voiced interval of Nv frames, means for determining the correspondence between the unknown digit voiced interval test signals a(n).sub.i and each identified digit (q = 1, 2, . . . , Q) voiced interval reference signals m.sub.iq comprising means for time aligning said test signals a(n).sub.i for the unknown digit voiced interval frames i = 1, 2, . . . , Nv to the average reference set voiced interval frames i = 1, 2, . . . , Nv to from a set of Nv aligned test signals a.sub.i ' corresponding to the Nv test signals a(n).sub.i, means jointly responsive to said aligned test signals a.sub.i ', R.sub.i, and said q.sup.th identified digit reference signals m.sub.iq for forming a signal ##EQU15## representative of the correspondence between said voiced interval test signals a.sub.i ' and said q.sup.th identified digit voiced interval reference signals m.sub.iq, and means responsive to said correspondence signals D.sub.1q for selecting the identified digit having the minimum correspondence signal D.sub.1q.
6. A speech recognizer according to claim 5 wherein said test signal generating means comprises means for producing a classification signal for the beginning frame of said unknown spoken digit as one of voiced, unvoiced, and silence; and further comprises means jointly responsive to said classification signal, said D.sub.1q correspondence signals and the identity of said identified digit having the minimum correspondence signal D.sub.1q for generating a first signal responsive to an inconsistency between said classification signal and the identity of said identified digit having the minimum correspondence signal D.sub.1q ; means responsive to said first signal for forming a second correspondence signal ##EQU16## for each q.sup.th identified digit q = 1, 2, . . . , Q; and means responsive to said second correspondence signals for identifying said unknown digit as the identified digit q having the least D.sub.2q correspondence signal.