9. A system comprising: one or more computer processors; and one or more non-transitory computer readable devices that include instructions that, when executed by the one or more computer processors, cause the one or more processors to perform operations, the operations comprising: obtaining aligned voice data that comprises untransformed voice data in a target language that has been aligned with phonemes in a corresponding textual transcript using a source acoustic model for a source language, wherein the source acoustic model includes information that maps acoustic features of the source language to phonemes in a transformed feature space, and the untransformed voice data is in an untransformed feature space; transforming the aligned voice data according to a particular transform operation, using the source acoustic model, to obtain transformed voice data; adapting the source acoustic model to the target language using the untransformed voice data in the target language to obtain an adapted acoustic model; and training a target acoustic model for the target language using the transformed voice data and the adapted acoustic model; and providing the target acoustic model in association with the target language.
16. The system of claim 9 , wherein the target language and the source language comprise languages that are different from each other.