9. The system of claim 1 , further comprising a database of recorded audio pieces the speech synthesizer can use and concatenate together to synthesize speech, wherein the database of recorded audio pieces includes audio pieces of non-lexical cues.
11. The system of claim 9 , wherein the audio pieces of non-lexical cues in the database include at least one of a non-verbal disfluency, a breathing noise, and a phonological gesture.