1. A method comprising: identifying an acoustic model, wherein the acoustic model is trained on native speech in a target dialect; transcribing collected speech from a speaker, to yield a lattice of plausible phonemes which depend on a property of the 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 the lattice of plausible phonemes.
3. The method of claim 1 , wherein the native speech represents a class of speakers.