In order to create a character that sounds believably human, Crypton uses a real person?s voice as the basis for the avatar?s distinct singing style. The adaptation of someone?s singing voice into a character that a user can program to sing anything has lead to controversy. Real musicians have been loathe to step forward and submit their voices for fear that they?ll be replaced by a virtual copy of themselves. Instead of professional singers, Crypton has hired cartoon voice actors to provide the basis for their avatars. Miku is reportedly created from the voice of
Saki Fujita.