HUMAN ECHOLOCATION: AN APPROACH TO BECOME HUMAN BATS
Mind
In recent years, it has revealed that humans, like bats, can navigate their surroundings by bouncing off echoes and analysing them. If learnable, this technique seems to be a godsend for the visually-impaired, allowing them to blend well within the society. But doubt lingers: could this hopefully constitute a promising relief from blindness?
Hiking in a rough terrain or mountain biking along unfamiliar trails, Daniel Kish seems like an ordinary person. The only thing bizarre is the consistent clicking of his tongue as he curves up and down, and intriguingly they are no nervous tics. He is just one of the bunch of human echolocators who — being born blind — picked up the remarkable skill of identifying their surroundings by making use of echoes in a way comparable to bats.
Echolocation has endured for ages. A process to detect surroundings by reflecting echoes off the surfaces of neighboring objects towards oneself and then examining them, echolocation has long been known to assist blind animals, such as bats and dolphins, to paint a picture of their environment. Although the first whiffs caught of this ability among humans date back to as remote as mid-sixteenth century, it has lately reignited an interest among the scientists and researchers, who now try to peek into how this marvelous feat is performed, and — perhaps more importantly — how it can be mastered by almost anybody. Yes, anybody!
Human echolocation, it is believed, is an aptitude that pops up spontaneously among blindly born children. These children are highly sensitive to their ambient acoustics and explore and experiment different ways to perceive their surroundings without the aid of eyes. Conceivably, this makes them stumble upon this extraordinary skill that is then adopted by them for the rest of their lives.
“From a scientific perspective, it’s firmly established that people can do this. We’ve found they end up doing similar things, even though they’ve developed the skill independently,” says Lore Thaler, a neuroscientist at Durham University, who led a recent work on human echolocation.[1]
Luckily among humans, the ability to echolocate is not restricted merely to sight-deprived people; rather, normal people share it too. Lately, modern technological advances have made it feasible for researchers to scan human echolocators’ brains while they echolocate. This has unveiled telltale signs that point towards the fact that in order to decipher information transmitted through echoes, these people tend to use visual parts of their brains. Further, it has also surfaced that anyone, with normal hearing ability, is able to embrace this technique well to make a mental sketch of sizes, locations or distances of objects to use it to maneuver round obstacles during walking — all this possible right after undertaking only a couple of training sessions.
Interestingly, scientists have also endeavored to probe into the obscuring potential of human echolocation. For this purpose, Thaler and her team presented each one from a group of eight expert echolocators with a challenge: could he/she determine whether a small dinner-plate sized object was being hovered about three feet away from his/her head at different angles by using echoes yielded from mouth clicks alone. It transpired that when the object was placed right in front of the subject’s face, he/she could easily discern its presence. However, as the object was slid along different angles from 45° to 90° to 135° and eventually to 180°, it became progressively harder for every subject to detect it, even though their mouth clicks became louder and louder so as to, perhaps, amplify the returning echoes. Specifically, with the object at 180° right behind their backs, the accuracy plummeted to almost 50% that translates to a mere guess. This shows that, indeed, human echolocation has limiting factors presently.
Nonetheless, our knowledge of human echolocation is incomplete. So far, we have only been able to enlighten ourselves with an inadequate amount of information pertaining to it, and, as Kish puts it, what we know about human echolocation could barely fill a bookshelf. There are still some aspects of it to which we are clearly oblivious, but by paving our way further into research, we can hopefully bridge the gap. Moreover, it is also speculated that humans may polish up their ability to echolocate with the passage of time and, who knows, render themselves to actually see as well with sound as well they do with eyes.
“Now, bats have had millions of years of evolution basically to develop these mechanisms to dynamically adjust their emissions,” remarks Thaler, “and what we were wondering is, well, do people do the same?”[2]
In short, human echolocation makes for a miraculous faculty. Despite that, there are still some short-comings tied to it currently that restrain us, especially unsighted among us, to fully adopt it as a substitute to eye vision. However, for the time being, it would be very well appropriate to term it as ‘an approach to become human bats’!
[1] “Echolocation Could Help Blind People Learn to Navigate like Bats | Blindness and Visual Impairment | The Guardian,” accessed June 7, 2021, https://www.theguardian.com/society/2018/feb/28/echolocation-could-help-blind-people-learn-to-navigate-like-bats.
[2] Christopher Intagliata, “Human Echolocators Use Tricks Similar to Bats,” Scientific American, accessed June 7, 2021, https://www.scientificamerican.com/podcast/episode/human-echolocators-use-tricks-similar-to-bats/.
Credits:
a) Fig.1 by Wiley Online Library
