blind as a bat ?

Thanks to a tweet from Peter (@PD_Smith) I was reminded of the issue of echolocation in blind humans, which appears to be so unknown in the UK that the BBC ran a news story on a child using the technique.

Goes to show that we live on an island – elsewhere it is quite common for blind people to tap their sticks very loudly and use the echo for orientation. I lived in Marburg for two years, where Germany’s national school for blind people is located, and the first thing to learn when you move to that city is to jump into the next ditch when you hear loud tapping sounds approaching. Well I’m only exaggerating slightly. Truth is, many blind people there walk around so fast and confidently that they are almost a danger to others.

I had considered this the normal state of affairs until a few years ago I came across the issue again when editing entries for a UK based encyclopaedia, where the entries for echolocation and blindness seemed to lack this piece of information. Doing a bit of research I found a text by Jim Blackshear, apparently written as teaching material. Apart from various interesting bits of history (apparently human echolocation was first observed by Diderot in 1749, so well done to the BBC for trying to sell it as news!), the text also contained the crucial information as to why the technique is unknown in some countries and common in others. Apparently, many people, especially when they are blind from an early age, develop the technique naturally, but in some places it is actively discouraged by education professionals.

Blackshear cites Robert Feinstein who writes in Bent Voices:

Sadly, echolocation is not talked about, nor is it taught. It's only learned intuitively or by example. I read about it only once, in a book called Follow My Leader, which claimed that an eleven-year-old boy, blinded by a firecracker explosion, had developed the skill. From all that I can tell, however, those blinded later in life almost never learn how to do it. I know a girl, blind at fourteen, who will walk smack into a wall, even though she has been blind for twenty-eight years. Once she walked straight into the closed door of my lobby. "Didn't you hear that door?" I asked incredulously. "Don't be a retard!" she countered, "you don't hear doors!" "I do!" I said, in my most condescending voice. "Yeah, right!" she said, and I supposed you hear traffic lights!" "I hate you damn sighted blind people!" I remonstrated, and changed the subject before we got into a fight.

As we grow older and learn to use canes or dogs we grow to rely less on the information gained from echolocation. The skill is there, but it can go dormant. Mobility instructors discourage echolocation, especially clicking. While training with my first dog, I forgot myself and clicked to determine if I was near a pole. The instructor told me that my dog would be taken from me if I continued to make "those sounds," that they served no purpose, that they made blind people objects of ridicule. And furthermore, I'd confuse the dog. I stopped clicking—until I returned home!

Now that really drove me up the wall when I read that he was discouraged from clicking. If you have the choice between not perceiving your environment at all, and perceiving it through echolocation while looking a bit silly, I think it is perfectly obvious what everybody would and should do. Discouraging people from using echolocation is to me like robbing them of their eyesight all over again.