Initially, we shall start by designing a distance to power mechanism by setting range finders in the x-y plane ahead of the user with at least a 180 degree field of view or use a camera and computer vision techniques. Current tasks are to define the rangefinder type(s) used, interfacing with the range finder (through an arduino uno) and re sending the visual data into sound (varying pitch, volume according to height and distance respectively)

If all goes well additional 360 degrees field of view with timbre varying (maybe square to sine wave) by angle

Here is a video with a brief explanation of the device and a block diagram of the system design:
http://youtu.be/WNOg-jXobKQ