Book excerpt: Our studies of aesthetics and knowledge have long tended to privilege the visual - at the expense, Wolfgang Ernst argues, of the aural. 'Sonic Time Machines' aims to correct that, presenting a striking new approach to theorising sound that investigates its split existence: as a temporal effect in a techno-cultural context and as a source of knowledge and information. Ernst creates a new term for the concept at the heart of the book, "sonicity," a flexible and powerful term that allows him to consider sound with all its many physical, philosophical, and cultural valences.