1. A method comprising: overgenerating, via processor associated with a speech processing system, potential pronunciations by converting portions of symbolic input into a number of possible lexical pronunciation variants based on an established set of conversion rules, wherein the symbolic input comprises labeled speech data; selecting, by the processor, pronunciations in a speech recognition context from the potential pronunciations, to yield selected potential pronunciations; retraining, by the processor, the established set of conversion rules based on the selected potential pronunciations to yield a retrained set of conversion rules; and processing speech based on the retrained set of conversion rules.