Abstract We introduce a mobile spatial interactive application that uses a combination of a GPS, inertial sensing, gestural interaction, probabilistic models and Monte Carlo sampling, with vibration and audio feedback. This system allows the probing or querying of targets in a local area, based on a model of the local environment and specific context variables of interest, to enable a rich, embodied and location–aware spatial interaction. An experiment was conducted to investigate how spatial target selection at different distances, target separations and target widths is affected by a system with added ‘typical’ noise characteristics. Results showed that the successful selection of targets in the virtual environment is maximised with a combination of high angular separation and angular width.

Audio-driven eyes-free interactions in which simultaneous audio streams are employed can overload the user. We propose the use of an audio minimization technique in a 3D audio interface that will allow the user to minimize streams while focusing on a different interaction. We first introduce the concept of audio minimization and then describe the design and evaluation of a study set out to investigate the requirements for audio minimization. Author Keywords 3D audio interfaces, audio minimization, divided attention.

As mobile devices increase in functionality, users perform more tasks when on the move. Spatial audio interfaces offer a solution for eyes-free interaction. However, such interfaces face a number of challenges when supporting multiple and simultaneous tasks, namely: 1) interference amongst multiple audio streams, and 2) the constraints of cognitive load. We present a comparative study of spatial audio techniques evaluated in a divided- and selective-attention task. A podcast was used for high cognitive load (dividedattention) and classical music for low cognitive load (selective-attention), while interacting with an audio menu. Results showed that spatial audio techniques were preferred when cognitive load was kept low, while a baseline technique using an interruptible single audio stream was significantly less preferred. Conversely, when cognitive load was increased the preferences reversed. Thus, given an appropriate task structure, spatial techniques offer a means of designing effective audio interfaces to support eyes-free mobile multitasking. Author Keywords Multitasking, audio interfaces, eyes-free interaction, cognitive load, divided-attention task, selective-attention task.