12. A computer system comprising: one or more computer processors; one or more computer readable storage media and program instructions stored on the one or more computer readable storage media, the program instructions comprising instructions to perform: conducting speech recognition on a channel recording of a conversation to provide time boundaries and written language corresponding to utterances within the channel recording; determining sentence or phrase boundaries for a transcription of the conversation; aligning written language within the one or more transcriptions with the written language corresponding to the utterances with the channel recording to provide sentence or phrase boundaries for the channel recording; and training a speech recognizer according to the sentence or phrase boundaries for the transcription and the sentence or phrase boundaries for the channel recording.
12. A computer system comprising: one or more computer processors; one or more computer readable storage media and program instructions stored on the one or more computer readable storage media, the program instructions comprising instructions to perform: conducting speech recognition on a channel recording of a conversation to provide time boundaries and written language corresponding to utterances within the channel recording; determining sentence or phrase boundaries for a transcription of the conversation; aligning written language within the one or more transcriptions with the written language corresponding to the utterances with the channel recording to provide sentence or phrase boundaries for the channel recording; and training a speech recognizer according to the sentence or phrase boundaries for the transcription and the sentence or phrase boundaries for the channel recording. 18. The computer system of claim 12 , wherein the sentence or phrase boundaries for the channel recording are determined without manual segmentation or silence-based automatic segmentation of the channel recording.