Bats may bring to mind vampires or a certain billionaire vigilante, but beyond fantasy and science fiction, they stand out thanks to their echolocation technique, which lets them understand their surroundings using sound. What began as a side project at the University of California has become Sonic Eye, an ultrasonic helmet that gives the wearer an echolocation system similar to that of bats.
The Myth of the Blind Bat
One of the many myths surrounding bats is that they are blind. While there are differences in eye development depending on the species, the phrase “blind as a bat” is simply false. Perhaps the myth developed because of their nocturnal activity (in the vast majority of cases) and their advanced use of echolocation to navigate and hunt. Frequency, composition, intensity, and interval of pulses are just four aspects that highlight the complexity of their echolocation. So, how could we not try to imitate that? Humans have a certain (though very limited) ability to echolocate, but bats have ultrasound on their side, and to even the score, we need a little technological help. That is how Sonic Eye was born.
How Sonic Eye Lets Humans Echolocate
At first glance, Sonic Eye looks like a helmet created by Doc Brown, but its function definitely justifies its current appearance. It all started when Jascha Sohl-Dickstein and his colleagues at the University of California in Berkeley wondered whether humans would need a special “neural wiring” to echolocate, or if the brain could adapt to the same amount of acoustic information that bats access. The subsequent development led to the creation of Sonic Eye, which emits ultrasonic chirps. The sound bounces off objects in the environment, and the echo is picked up by a pair of “bat ears” (technically auricular pavilions) with a microphone at their center. A computer processes the echo using downsampling by a factor of 20, so that humans can hear it.
Promising Tests and a Smaller Future
During testing, Sonic Eye proved so accurate that its users (especially the most trained) could recognize a difference of just twenty centimeters in the position of a plate on a table. But the most striking thing here is that the human brain has an excellent ability to create mental maps through sound, just like bats do. The next step is to miniaturize the Sonic Eye design, since it currently requires carrying a laptop computer in a backpack. With enough adjustments, the helmet could adopt a much lighter format, while the acoustic processing would be handled by a smartphone.
