1. A method comprising: identifying an acoustic model and a pronouncing dictionary, wherein the acoustic model and the pronouncing dictionary are trained on native speech in a target dialect; collecting speech from a speaker, resulting in collected speech; transcribing the collected speech to generate a lattice of plausible phonemes which depend on a property of the target dialect; replacing each phoneme used 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, to yield a modified acoustic model; and recognizing, via a processor, additional speech from the speaker using the modified acoustic model.