Things You'll Need
Instructions
Select "Sparring" mode from the main menu. Select a character and complete an exercise session with that character. After the training session, you will have the ability to choose the voice of that character to be heard the during the match.
Complete a training exercise for all the characters to unlock all their voices. Note that the character of Ein does not have a voice, but complete the training session anyway.
After completing all the character training sessions, go to the settings menu and find that the Alpha-152 voice will be unlocked. Select "Alpha-152" and return to the main menu. Choose a game and the voice of Alpha-152 will play during your next match.