20. The method of claim 19, wherein the step of producing smoothed probabilities includes the steps of: (r) dividing the short string of labels into two portions; (s) applying a forward-backward algorithm, which is based on the updated probabilities, to the first portion of labels to generate counts C.sub.1 (F.sub.2 (l), A.sub.ij) and C.sub.1 (A.sub.ij) and a probability P.sub.1 (F.sub.2 (l).vertline.A.sub.ij) for each label output; (t) applying a forward-backward algorithm, which is based on the last update probabilities, to the second portion to generate counts C.sub.2 (F.sub.2 (l), A.sub.ij) and C.sub.2 (A.sub.ij) and a probability P.sub.2 (Fhd 2(l).vertline., A.sub.ij) for each label output, and (u) evaluating a factor .lambda..sub.m to maximize the likelihood the expression: ##EQU29## where P.sub.o represents an initial probability and wherein S.sub.m represents an mth class of M transitions where transitions are classified based on transition count value.
20. The method of claim 19, wherein the step of producing smoothed probabilities includes the steps of: (r) dividing the short string of labels into two portions; (s) applying a forward-backward algorithm, which is based on the updated probabilities, to the first portion of labels to generate counts C.sub.1 (F.sub.2 (l), A.sub.ij) and C.sub.1 (A.sub.ij) and a probability P.sub.1 (F.sub.2 (l).vertline.A.sub.ij) for each label output; (t) applying a forward-backward algorithm, which is based on the last update probabilities, to the second portion to generate counts C.sub.2 (F.sub.2 (l), A.sub.ij) and C.sub.2 (A.sub.ij) and a probability P.sub.2 (Fhd 2(l).vertline., A.sub.ij) for each label output, and (u) evaluating a factor .lambda..sub.m to maximize the likelihood the expression: ##EQU29## where P.sub.o represents an initial probability and wherein S.sub.m represents an mth class of M transitions where transitions are classified based on transition count value. 21. The method of claim 20, wherein the step of producing the smoothed probabilities further comprises the step of: (v) computing: ##EQU30## wherein .lambda..sub.m is a selectable weighting factor and wherein A.sub.ij represents a transition from a state i to a state j in a phone machine.