Comment by pvaldes
Hum, that last idea deserve more time
I want to propose this system. Imagine that you are on a workplace where blind people came often to work or as clients. There is a soft, low, slow and sparse music that is pleasing to hear as a background for anybody and is always changing.
Now lets imagine that this music is codified and played on a 3D system.
Every time we hear a piano note it means "door here", all bass notes mean "danger/stairs" and a flute means for example "WC". That would be awesome for blind people navigating new places without interrupting other workers asking for directions. Each one of this signals would be played on intervals of one minute or more, never less, so most of the time you have either silence or pleasant sounds that don't bother other people and the notes played by a particular instrument are changed each time for the same reason.
If we need more information, we could add short cords from popular music to convey additional words. For example a <garage door> could play on piano the four note sequence "here on my car" from Gary Numan, or iterate over a list of similar parts of very popular songs with the word "car" on it to not be too repetitive.
Of course it just could also just say "garage door" when a modified white cane approach like on elevators, but that could be distracting for non blind workers.
Systems like that have existed for decades in various versions. The only blind people who use them are people who went blind as an adult - and then often only the investor. People who went blind young have learned to deal with the world and discover technology like that is more annoying than helpful.
Dogs and canes work very well and solve most of the problem. It doesn't really matter if they are walking into a wall, piano or door - they need to know to avoid it. If you want useful sounds require every traffic light to have beeps when it is safe to cross loud enough to be heard across the street - because that is a real problem blind people have in navigating. Most of the rest of the world is forgiving to the types of mistakes blind people make and so they don't really need help.
The other way you can help the blind is just be willing to give directions from the sidewalk in front of a building to the front door.