2. The method of claim 1 wherein step (c) includes: (c1) predicting intelligibility of the synthesized speech; and (c2) determining that the predicted intelligibility from step (c1) is lower than a minimum threshold.
2. The method of claim 1 wherein step (c) includes: (c1) predicting intelligibility of the synthesized speech; and (c2) determining that the predicted intelligibility from step (c1) is lower than a minimum threshold. 3. The method of claim 2 further comprising, between steps (c) and (d): (f) adapting a model used in conjunction with step (d).