Sound Pressure reveals how speaker systems mounted in public, employment, military and entertainment environments have played a pivotal role in the way that humans have been physiologically and psychologically organised and disciplined throughout the past century. The networked Wired Radio speakers of the 1920's industrialised factory, acoustically anchor a narrative based on the functional utilisation of sound systems for insidious purposes; from the surround-sound techniques of the Waco siege, to the application of sonic torture in Guantánamo and Abu Ghraib. Crucially, Sound Pressure identifies the logic behind the miniaturisation and disappearance of visible sound system technologies as they transmute into the ultrasonic dynamics of the Hypersonic Sound System and covert bone conduction techniques of Whispering Windows. The book charts an evolution of speaker technology that has been, and will be, used to influence, manipulate and torture the collective and isolated body. It amplifies the connections between LRADs, iPods, Mosquitos, Intonarumori, loudhailers, and Sequential Arc Discharge Acoustic Generators - the meta-network of speaker systems through which rhythms and cadences of power are transmitted, connected, and modulated.