Daniel Kish on how he's able to use echolocation:
Edit: Another neat factoid is that there were experiments done where subjects wore glasses that turned the world upside down or mirrored left and right. After about a week people could function normally while wearing those. The brain knows what the world is supposed to look like and is able to figure out the correct transform, and once applied previously learned motor skills are once again fully available. This shows that there is some kind of stable higher level representation that sight feeds into in a flexible way.
I think most people use sound all the time to orient themselves, especially in the dark. It's just that we are so fixated on what we see that using hearing to tell what is around you gets overloaded by the higher resolution information from our eyes.
I think I would be very interesting to see good research done with blind people to see how they use their senses. Is anybody aware of such research?
https://en.wikipedia.org/wiki/Daniel_Kish
"Kish's work has inspired a number of scientific studies related to human echolocation. In a 2009 study at the University of Alcalá in Madrid, Spain, ten sighted subjects were taught basic navigation skills within a few days. The study aimed to analyze various sounds which can be used to echolocate and evaluate which were most effective.[5][6] In another study, MRI brain scans were taken of Kish and another echolocation expert to identify the parts of the brain involved in echolocation, with readings suggesting "that brain structures that process visual information in sighted people process echo information in blind echolocation experts."
> Isn't it just a matter of listening to the ambient noise in your environment. open space sounds different to a closed room.
Yes. Absent of light and suitable noise, you make the noise yourself. And this is something instinctive to me, so i would assume other people could do it, too.
Echolocation is contentious because people assume it's to do with timing.
Humans can't time the echo in a room.
Echolocation by humans is using the head as a dampener between the ears to get direction/distance by diffing the ears on noise not time.
Is my understanding.
You could see why people who think it's related to timing like the classic submarine would obviously think it doesn't work with humans. You learn about the speed of sound at a young age and people know the brain can't handle that.
They might assume in a dark room people are using ambient noise and ambient echo's, not echolocation. With people using echolocation who are visually impaired in most articles they are not 100% blind so you are not sure what mix is going on.
Most articles aren't explaining this well.
I find it hard to imagine what learning such a skill entails.
The echo pulses are there but just milliseconds after the sound you made. It will all blur into a softer or harder reverb depending on your surroundings.
To hear an actual separate echo pulse, it would need to be 20-100 milliseconds later than the original sound. That corresponds to a large hall tens of meters in size.
The difference in the sound response is subtle but clear. It's like tweaking the knobs of a reverb effect in an audio processing software.
It is not about detecting discrete echo pulses like a radar or a sonar does, it's about sensing a change in the "tone" of the sound you make.
In signal processing terms you're "measuring" the impulse response of the room around you.