Spatial sound rendering for assisted living on an embedded platform

3-D sound can be used to synthesize audio stimuli able to describe spatial information. This can be used as a sensorial substitution of sight for the visually impaired to help them in the task of autonomous orientation and mobility. However, commonly used techniques are computational demanding, therefore not optimal for being implemented in embedded systems. Moreover, the sound localization is specific to each individual and complex to measure or customize. We chose to develop a bottom-up physical model to synthesize a simplified transfer function and playback audio signals over headphones. The model permits the computational requirements to be reduced at the cost of lower accuracy of representation. Still the proposed system can meet the goal of describing spatial information to the listener. Moreover, it can be a promising solution for on-the-go individualization. In this paper we describe the algorithm, the implementation on an embedded platform and present the comparison between HRIR-based synthesis and the proposed simplified physical approach.