At-will, std, touch or eye contact; you take control of the subject's voice. The subject can no longer speak or use powers that require speech, and when you speak, you can use their voice. If the subject has any spells, minions, or devices that respond to their voice, they will obey your commands. If they have any supernatural abilities based on voice alone, such as bardic music (but not ordinary spellcasting), you can use their abilities.