The power to project one's voice great distances or even into a room without being physically present. Technique of Voice Manipulation.
The user can make their voice come from somewhere else, even great distances or somewhere where the user isn't physically present.
Motoki Yaze (Strike the Blood) can use this ability by using drug; more than one pill allows him to create a sound clone of himself and control it by concentrating while wearing his headphones.
Shaher (Shakugan no Shana) is the god of guidance and as such her voice will reach everyone in the world and absolutely cannot be blocked by any means.