14. A system comprising: a processor; and a computer-readable storage device having instructions stored which, when executed on the processor, perform operations comprising: receiving automatic speech recognition output of a plurality of speech interactions with a user; receiving an automatic speech recognition transcription error model characterizing how automatic speech recognition transcription errors are made; generating, via a processor, guesses of a true transcription and a user model via an expectation maximization algorithm, wherein the expectation maximization algorithm is based on the error model and the respective automatic speech recognition output; and generating a personalized user model associated with a user voiceprint of the user based on the guesses and the user model.
14. A system comprising: a processor; and a computer-readable storage device having instructions stored which, when executed on the processor, perform operations comprising: receiving automatic speech recognition output of a plurality of speech interactions with a user; receiving an automatic speech recognition transcription error model characterizing how automatic speech recognition transcription errors are made; generating, via a processor, guesses of a true transcription and a user model via an expectation maximization algorithm, wherein the expectation maximization algorithm is based on the error model and the respective automatic speech recognition output; and generating a personalized user model associated with a user voiceprint of the user based on the guesses and the user model. 16. The system of claim 14 , wherein generating the guesses of the true transcription and the user model further comprises repeating the following steps until a threshold is met: guessing the true transcription from a current guess of the user model, to yield a current guess of the true transcription; and guessing the user model from the current guess of the true transcription.