The Italian giallo film was a type of thriller that was produced in huge numbers between the early 1960s and the late 1980s. This thesis contributes to recent scholarly attempts to situate the giallo within its socio-cultural historical context but resists the critical tendency to read these films as passive and transparent reflections of social attitudes in post-war Italy. Rather, I attend concretely to the form of these films and, specifically, to their critically neglected sound designs. I argue that the giallo’s voice tracks were conditioned by the commercial imperatives of Italy’s post-war popular film industry and that these commercial imperatives were in turn shaped by wider social, economic and political phenomena. By theorising the voice as a mediator between the giallo text and its industrial and social contexts, I show that these films both registered and reified social change. Chapter 1 demonstrates that the anonymous narrator of Mario Bava’s The Girl Who Knew Too Much (1963) adopts a range of sonorous modes throughout the film. Each of these sonorous modes invokes a specific set of intertexts which are vital to tracing both the giallo’s cultural origins and the increasingly globalised socio- cultural landscape from which it emerged. This chapter then shows that Dario Argento’s The Bird with the Crystal Plumage (1970) uses the model of the cinematic voice-over to explore the subjective experience of urban space in post-war Italy. The film suggests that by 1970 the ability to vocally ‘narrate’ and thus control space had become a fundamental assumption of the modern, cosmopolitan subject. Chapter 2 analyses Lucio Fulci’s Don’t Torture a Duckling (1972) and Sergio Martino’s Torso (1973). Both films draw on longstanding Italian cultural stereotypes to pitch the silence of the rural against the vocality of the urban. The films use silence and the voice as ‘cartographic’ tools to delineate the profound socio-economic divisions between Italy’s rural South and its more urban North, but they also illustrate the giallo’s underlying affinities with its silent cinema ancestors and so challenge the assumed temporal borders between cinematic eras. Chapter 3 argues that Argento’s Tenebrae (1982) and Fulci’s The New York Ripper (1982) variously mimic the vocal aesthetics of television. These films lay bare both the increasing dominance of the Italian cultural landscape by imported commercial television in the 1980s and the neoliberal economic project that underpinned that trend. Ultimately, they question the stability of the nation itself, precisely because the voice — now fractured across a global mediascape — is unable to signal national specificity.