1. A system comprising: a computer-readable memory storing executable instructions; and one or more physical computer processors in communication with the computer-readable memory, wherein the one or more physical computer processors are programmed by the executable instructions to at least: automatically predict pronunciations using a grapheme-to-phoneme model for a list of words having manually provided pronunciations, wherein the grapheme-to-phoneme model is adapted to generate a predicted pronunciation and a confidence score for the predicted pronunciation based upon an input word; generate a prediction performance model for the grapheme-to-phoneme model based on: a comparison of automatically predicted pronunciations of the list of words with the manually provided pronunciations for the list of words, and confidence scores for the automatically predicted pronunciations, wherein the prediction performance model is adapted to generate performance information for the grapheme-to-phoneme model, the performance information indicating a degree of confidence in the grapheme-to-phoneme model to predict a new word added to the system based upon an input predicted pronunciation generated by the grapheme-to-phoneme model for the new word and the confidence score for the input predicted pronunciation generated by the grapheme-to-phoneme model; receive an electronic record including candidate words to be added to an automatic speech recognition lexicon, the automatic speech recognition lexicon including words having the automatically predicted pronunciations generated by the grapheme-to-phoneme model; generate, from the grapheme-to-phoneme model, a predicted pronunciation for a candidate word and a confidence score for a candidate word, wherein the candidate word is included in the candidate words; generate, from the prediction performance model, an annotation priority for the candidate word based on the confidence score for the predicted pronunciation of the candidate word and the predicted pronunciation of the candidate word; determine that the annotation priority for the candidate word exceeds a priority threshold; and route the candidate word to a manual pronunciation generator.