"Yapper" (Level 4) is the final antagonist of the game and the most difficult level due to him being the most violent of the antagonists. He'd been assassinated during a live performance and had been wandering in the forest instead of the hospital. 

Him being a singer makes his voice the most crucial part of the horror as the officer had to be weary of his voice getting closer or further. 

His voice is very radio-centric and sings oldies melodies.