4. The method of claim 1 , further comprising determining one or more target HMMs that correspond to one of the one or more phonemes included in the one or more linguistic targets, wherein each of the one or more HMMs is trained from a corpus of recorded speech units and estimates one or more spectral features of a corresponding linguistic target over N states.
12. The method of claim 4 , further comprising: determining whether the selected sequence includes an HMM; and in response to determining that the selected sequence includes an HMM, updating the HMM based on one or more FSMs.