37. A system for speech synthesis comprising: a processor; and a storage medium having program instructions written thereon for execution on the processor, the program instructions including program instructions for: a front end module configured to receive symbolic input descriptive of an utterance to be synthesized, a back end module configured to select one or more portions of the utterance to be constructed from certain Phone-and-Transition (P&T) speech units that function as prototype speech units, the prototype speech units obtained from a speech corpus, the speech corpus including speech units recorded from a human speaker, a unit engine of the back end module configured to apply Phone-and-Transition (P&T) adaptations to selected ones of the prototype speech units of the speech corpus that are derived from a context different than one in which they are to be used in the utterance, to produce adapted speech units that are contextually appropriate for the utterance, and a concatenation engine of the back end module configured to concatenate at least the adapted speech units from the speech corpus to produce a speech waveform for the utterance.
38. The system of claim 37 wherein the P&T speech units comprise one or more phones and transitions.