Though graphic novels are slowly being accepted into the world of academic criticism, one fundamental aspect of the medium has been consistently ignored, dismissed, and ridiculed as a crude necessity: textualized sound. Visual onomatopoeias, most recognizably depicted as sound effects for gunshots, car chases, and the like, have a long history in the medium of comics. Though these textualized sounds may have originated as a device of necessity—a clumsy means of employing sound into a “mono-sensory medium” (to quote Scott McCloud)—the implementation of onomatopoeia in comics has become an integral device in defining an author’s style and heightening their work. This creative, purposeful implementation of sound is epitomized in the work of renounced graphic novelist Frank Miller. This paper argues that, in his works Sin City and Batman: The Dark Knight Returns, Miller uses sound to reflect themes present in his work, heighten the sense of physical space within and beyond panel borders, contribute to plot, evoke texture, or embody character. The violent sound effects Miller implements in these works redefine the possibilities of this integral comic component. Miller aligns himself with the tradition of sound effects in comics while simultaneously demonstrating the experimental possibilities of this device.