Eyes-free multitasking

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 (divided-attention) 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.