As an experimental project a few years ago, I created a prototype app that converts what the iPhone depth-camera sees into 3d audio. I was able to demonstrate that we could navigate crowded areas using sound to hear what was visually around us.

Here is a demo video that demonstrates walking a NYC sidewalk. You'll want headphones to hear the audio effects. Youtube removes a lot of the "3d spatial audio" effects from the original app but you can still get an idea of what it was trying to do: $1

The visuals were just for debugging, it's demonstrating the depth the camera was detecting. And the frequency changes indicate movement of an object. Apologies for the audio in the original, it was a first test. I also had a version I was experimenting with that translated different colors to different frequencies in 3d audio space.

I never knew if this was a dumb idea, an idea that already exists out there, or if anyone would care or would be interested in such a thing. It's been a few years and I've always wondered if it had any value.