Sound Directions investigates the models built into contemporary signal processing technologies for sound. Before commercial audio reaches speakers or iPods, it has been run through a vast array of signal processing technologies-from preamplifiers, to special effects, to spatial modelers-that play a crucial role in the quality and style of the sounds we hear. These background devices endow recorded and reproduced audio with the sheen, stylization and intelligibility that listeners have come to expect. Each background audio technology has a "sound" that it imparts to all audio that passes through it-even those technologies sold to users as "transparent." Yet because they are largely used by specialists like musicians, recording and broadcast engineers, artists, architectural acousticians and sound designers, they have received little critical attention from scholars and the press. Yet these apparently aesthetic and technical concerns carry with them a range of political and cultural values. By examining the models that form the basis for much contemporary signal processing, Sound Directions will reorient debates over the contemporary urban soundscape. Funded by a SSHRC Standard Research Grant, 2009-2012 with additional support from the Annenberg Foundation and the Center for Advanced Study in the Behavioral Sciences at Stanford University.