When George Du Maurier’s infamous mesmerist Svengali performs on his elastic penny whistle, the instrument produces a sound “more human almost than the human voice itself.” The suggestion that a voice could be more, or conversely less, human calls attention to the precariousness of a category under threat in the nineteenth century. My project confronts the enigmatic nature of voices in transatlantic Gothic fiction in relation to definitions of the human, attending to figures that frustrate taxonomic classification in sonic as well as visual terms. Discussions of stethoscopic listening, physiognomy, vivisection, and mesmerism in Britain and the United States frame my chapters, underscoring a nineteenth-century preoccupation with embodiment foundational for both literary and medical knowledge. Through an analysis of bodies as soundscapes in the work of Edgar Allan Poe, Robert Louis Stevenson, and H.G. Wells, among others, my project discovers an attention to voice as a recalcitrant force that subverts scientific authority over bodies. Michel Foucault’s The Birth of the Clinic famously establishes the authoritative gaze as rendering bodies knowable, but I contend that the audible world remained a contested and occulted space that resisted classification. Sound was central to nineteenth-century investigations of the human. In the texts I examine, characters confront the sonic qualities of corporeal beings, which challenge them to listen in unconventional ways. Although the listening practices necessary to interpret these qualities are often disorienting, they enable characters to recognize networks of influence that reshape the conditions of embodiment, which had become what William A. Cohen describes as the “untranscendable horizon of the human.” These connections offer the possibility of meaningful interaction yet simultaneously endanger the listener. In the unsettled realm of Gothic fiction, sound is framed as a force that can both empower and disempower bodies as it circulates within and between them. Establishing a new awareness of bodies as soundscapes in their own right, Sounding Bodies and Voices elucidates how Gothic works draw on nineteenth- century scientific practices to reimagine the contours of the human.