9. The computer program product of claim 8 , wherein utterances of the training source speech are not parallel to utterances of the training target speech.
9. The computer program product of claim 8 , wherein utterances of the training source speech are not parallel to utterances of the training target speech. 10. The computer program product of claim 9 , wherein the first executable portion further comprises instructions for training the first voice conversion model to convert the training source speech to synthetic speech corresponding to the training source speech in which the synthetic speech is generated by a text-to-speech device having parallel text corresponding to the training source speech.