A Survey on the Affordances of “Hearables” <s> Compass <s> / The physical world can be augmented with auditory cues allowing passive interaction by the user. By combining active badges, distributed systems, and wireless headphones, the movements of users through their workplace can trigger the transmission of auditory cues. These cues can summarize information about the activity of colleagues, notify the status of email or the start of a meeting, and remind of tasks such as retrieving a book at opportune times. We are currently experimenting with a prototype audio augmented reality system, Audio Aura, at Xerox PARC. The goal of this work is to create an aura of auditory information that mimics existing background, auditory awareness cues. We are prototyping sound designs for Audio Aurain VRML --ln L.“. <s> BIB001 </s> A Survey on the Affordances of “Hearables” <s> Compass <s> Audio augmented reality systems overlay the physical world with a virtual audio space. Today's smartphones provide enough processing power to create the impression of virtual sound sources being located in the real world. To achieve this, information about the user's location and orientation is necessary which requires additional hardware. In a real-world installation, however, we observed that instead of turning their head to localize sounds, users tend to turn their entire body. Therefore, we suggest to simply measure orientation of the user's body - or even just the mobile device she is holding - to generate the spatial audio. To verify this approach, we present two studies: Our first study in examines the user's head, body, and mobile device orientation when moving through an audio augmented reality system in a lab setting. Our second study analyzes the user experience in a real-world installation when using head, body, or device orientation to control the audio spatialization. We found that when navigating close to sound sources head tracking is necessary, but that it can potentially be replaced by device tracking in larger or more explorative usage scenarios. These findings help reduce the technical complexity of mobile audio augmented reality systems (MAARS), and enable their wider dissemination as mobile software-only apps. <s> BIB002
The technological affordances offered by placing a digital compass within a headset have implications for audio augmented reality (AAR) applications. AAR involves presenting users with context-specific audio information, often for highlighting local features within a museum or other place of public interest  BIB001 . Research has found that the placement of a digital compass on the head, as opposed to other locations on the body, results in the best subjective ratings of realism in AAR situations BIB002 , largely because ear-mounted compasses remain in fixed position to the eyes. For the same reason, ear-mounted compass information also offers important affordances for improving heading information within audio-based navigation applications.