Try on your phone using http://output.jsbin.com/kaxasu/
Note there is a bit of code to handle mobile and desktop differently. This is due to browser security and there is no way around it. This will be the same for Videos and 360Videos so make sure you are understand how it works. For details for example new video policies for iOS.
Did you try with your headphones? Try again. Put the right headphone in the right ear, the left...
Yes VR is about immersion but it's also about manipulation. How can sound be used to manipulate attention? Think about a system linked with animation, might useful tomorrow.