Board Thread:General Discussion/@comment-25352448-20140923005915/@comment-53539-20140924201651

Serza5 wrote: AcobraL wrote: Of course such a voicebank would be useless if that weren't the case.
 * points to Miku English, as well as KAITO English & MEIKO English and upcoming Rin/Len English*

The providers were given English classes, so they still had to learn some degree of proficiency in the language.