I have used the two Arduino Uno boards fitted with the Mp3 shields and HC-SR04 ultrasonic sensors to make a basic prototype for this stage of my project. I have loaded up some basic sound samples to the board to be triggered when the user is in close proximity to any objects detected by the left/right sensors fitted on a pair of glasses. The code I used was only around 100 lines which is not that much.

I have filmed a beta user wearing this in order to see the effectiveness of this prototype. He just wore the goggles and walked around the room, trying to navigate himself out of harm's way. It went out Ok but still wasn't 100% reliable.

The next stage would be to try this device out with a Raspberry Pi and try to make the sensors communicate with the board through bluetooth and also to some wireless headphones via bluetooth also.