For as long as recording and communications technologies have existed, ultrasound and other inaudible frequencies have been evoked to access the anomalous zones of transmission between the realms of the living and the dead. For the past ten years the AUDINT group has been researching peripheries of sonic perception (unsound) and the portals they open to new dimenasions, activating a continual intersection between fiction and fact, and pressuring thought to become something other than what it has been. The 64 short essays in this volume probe how unsound serves to activate the undead. Contributors from a variety of disciplines chart these warped zones, mapping out a zigzag timeline stretching from the 8th century BC (the song of the Sirens) to 2013 (acoustic levitation), and speculatively extending into 2057 (the emergence of holographic and holosonic phenomena). With texts by: Lawrence Abu Hamdan, Lendl Barcelos, Charlie Blake, Lisa Blanning, Brooker Buckingham, Al Cameron, Erik Davis, Kodwo Eshun, Matthew Fuller, Kristen Gallerneaux, Lee Gamble, Agnès Gayraud, Steve Goodman, Anna Greenspan, Olga Gurionova, S. Ayesha Hameed, Tim Hecker, Julian Henriques, Toby Heys, Eleni Ikoniadou, Amy Ireland, Nicola Masciandaro, Ramona Naddaff, Anthony Nine, The Occulture, Luciana Parisi, Alina Popa, Paul Purgas, Georgina Rochefort, Steven Shaviro, Jonathan Sterne, Eugene Thacker, Dave Tompkins, Shelley Trower, and Souzana Zamfe.