[Nasrudith]

I managed to discover that on my own when bored and walking around both in the dark and while waiting for a ride to arrive. Although it was a different technique.

I noticed that I could make a continuous sound and it would correspond roughly with the distance and gave me a one-dimensional relative distance detection from my head. A 'hissing' sound worked best for continuous reading while being subtle. It was pretty easy for me but it might have to do with being on the autistic spectrum and hypersensitivity.