15. A computer-readable storage device having instructions stored which, when executed by a computing device, result in the computing device performing operations comprising: identifying an acoustic model, wherein the acoustic model is trained on native speech in a target dialect; and replacing a phoneme in the acoustic model with a modified phoneme, wherein the modified phoneme is a weighted sum of plausible phonemes in a lattice of plausible phonemes associated with a class of a speaker.
15. A computer-readable storage device having instructions stored which, when executed by a computing device, result in the computing device performing operations comprising: identifying an acoustic model, wherein the acoustic model is trained on native speech in a target dialect; and replacing a phoneme in the acoustic model with a modified phoneme, wherein the modified phoneme is a weighted sum of plausible phonemes in a lattice of plausible phonemes associated with a class of a speaker. 19. The computer-readable storage device of claim 15 , wherein the replacing of the phoneme in the acoustic model is based on evaluating an objective function.