The animals we refer to as bats (“microbats,” really) are nocturnal animals — they sleep during the day, waiting until nightfall to forage for food. While one initially may conclude that these bats have superb night vision, if anything, it is the opposite: bats, by and large, do not see very well at all. Instead, they use sound — a series of high pitched clicks, typically outside of typical human hearing. (One type of bat uses a noise within the human hearing spectrum; click the blue-circled arrow here to hear it.) The sounds bounces off objects nearby and returns to the bat, which processes the sounds to get a “visual” image of its surroundings. This ability is called “echolocation,” and it’s not used only by bats — dolphins and some whales employ echolocation in lieu of sight.
And people can use it too. Just ask Daniel Kish, pictured below.
Kish is a 44 year old California man who, at 13 months old, lost his eyes — yes, not just his eyesight, but the eyes themselves — to retinal cancer. Where his eyes should be are, instead, holes, filled typically with non-functional prosthetic eyeballs. But despite the disability, Kish’s familiarity with his environment approaches that of a sighted person. Kish now navigates the world using echolocation, much like a bat does — with exceptional results.
In May, Kish gave an interview to Men’s Journal, where he demonstrated his bat-like ability, which he terms “FlashSonar.” With his tongue, he made a sharp click, and waited the split-second needed for the sound to rebound, muted but audible to one listening for it. From this, he is able to get an accurate-enough image of the world around him. For example, when the Men’s Journalauthor parks too far from the curb, Kish clicks — and notices first. And he can — and does — ride a bicycle, as seen here.
FlashSonar, however, does not come without controversy. Many in the blind community perceive Kish and his actions as a negative, bringing an unwelcome eccentricity to the table. (Clicking, as some point out, is not something people typically do in otherwise normal conversation.) But for those who believe echolocation to be empowering and wish to give it a try, Kish has set up a non-profit called World Access for the Blind, taglined “Our Vision is Sound.”
Bonus fact: In 1985, researchers at the University of California, Riverside, sewed shut the eyes of a baby monkey they named Britches. The researchers equipped Britches with a sonar device, in hopes of finding ways for blind human children to “see” without vision. The experiment ended when Britches (and hundreds of other animals) was taken from the lab by members of the Animal Liberation Front. Britches’ sutures were eventually removed, and he was repatriated into a family of macaques.
From the Archives: Temporary Blindness: Every day, for about forty minutes (non-consecutively, thankfully), each of us is functionally blind. Here’s why.
Related: “Talking With Your Hands, Listening With Your Eyes: A Complete Photographic Guide to American Sign Language,” by Gabriel Grayson. Forty-eight reviews, 44 of which are for five-stars. Available on Kindle.
This month, Now I Know is also brought to you by:
|More than 5 million people use MailChimp to design and send email marketing campaigns. Join them today.|
|uBiome is a startup that wants to help you to learn more about your microbiome. Discover how the trillions of bacteria in your body are keeping you healthy.|
|Listen to a best selling book today. Monthly memberships start at $7.95.|
Thank you to this month's sponsors!