13. A computer-readable storage device having instructions stored which, when executed by a computing device, result in the computing device performing operations comprising: identifying, in a database of utterances, transcribed utterances and un-transcribed utterances; ordering transcription candidate utterances from the un-transcribed utterances based on confidence scores of the transcription candidate utterances, to yield a selectively sampled order; transcribing, via a processor, a top n utterances from the selectively sampled order, to yield additional transcribed utterances and remainder un-transcribed utterances, wherein the remainder un-transcribed utterances are the un-transcribed utterances without the additional transcribed utterances; receiving human-transcribed utterances, wherein the human-transcribed utterances are selected from the remainder un-transcribed utterances for human transcription based on the confidence scores; and adding the additional transcribed utterances and the human-transcribed utterances to the database of utterances.
14. The computer-readable storage device of claim 13 , having additional instruction stored which result in the operations further comprising determining the confidence scores using an acoustic model.