AltAR/table: A Platform for Plausible Auditory Augmentation

Abstract

Auditory feedback from everyday interactions can be augmented to project digital information in the physical world. For that purpose, auditory augmentation modulates irrelevant aspects of already existing sounds while at the same time preserving relevant ones. A strategy for maintaining a certain level of plausibility is to metaphorically modulate the physical object itself. By mapping information to physical parameters instead of arbitrary sound parameters, it is assumed that even untrained users can draw on prior knowledge. Here we present AltAR/table, a hard- and software platform for plausible auditory augmentation of flat surfaces. It renders accurate augmentations of rectangular plates by capturing the structure-borne sound, feeding it through a physical sound model, and playing it back through the same object in real time. The implementation solves basic problems of equalization, active feedback control, spatialization, hand tracking, and low-latency signal processing. AltAR/table provides the technical foundations of object-centered auditory augmentations, for embedding sonifications into everyday objects such as tables, walls, or floors.