Photograph by Dan Winters
The space before the blind man was a riddle he needed to solve. Was he facing a house, a car, a hedge, a fence, a tree, or open space?
Ryo Hirosawa pushed the tip of his tongue hard to his palate and made a sharp click. He tried to focus on the form and timing of the click’s echo as it came back to his ears, as fast as a blink. But he couldn’t quite decipher the shape of the sound. Was it scattered, as if it’d hit foliage? Was it a clean pulse ricocheting off a stucco wall? Or was it hitting multiple objects and coming back in fragments, milliseconds apart?
“Are there solid objects in here, or are there sparse objects in here?” asked his instructor, Brian Bushway, who is also blind.
Hirosawa clicked; edges in the acoustic landscape slowly emerged. “There is a tree, I think, here, which is tall, and I see a house behind,” he said.
They stepped into the yard to find out whether he was right. Bushway, 33, tapped his cane against the tree trunk and reached up to grab a branch and shake the leaves. “Sparse objects,” he said. “Feel it; know what it sounds like.”
He knocked the wood panel of a wall. “A house,” Bushway said. “Awesome, very good.”
This quiet cul-de-sac in Long Beach, California, is at the center of an unorthodox movement to teach blind people to navigate using tongue clicks for orientation. Blind pioneer Daniel Kish, 50, founded World Access for the Blind in 2000 and runs it out of his home here. His students learn to better perceive the space before them, sending out sonar, like dolphins or bats, to get an acoustic read on their surroundings—a human form of echolocation.
Kish has worked with numerous scientists to study how the brain accomplishes this. A brain-imaging study on Kish and Bushway by researchers at the University of Western Ontario found that when they were echolocating, they were processing acoustic information in the spatial-visual part of the brain, not the part normally associated with hearing.
Kish had retinal cancer when he was born and lost both eyes soon after his first birthday. He unconsciously began making clicking noises with his tongue to navigate, as blind children often do.
But unlike many parents who worried their children might be ostracized, his mother and father didn’t discourage him from clicking, and they let him roam the neighborhood like any other 1970s kid. He rode bikes, climbed trees, and delivered his mom’s Avon catalogs to neighbors. He didn’t understand how the clicking was helping him until he was 11, when a friend pointed out that he was doing what bats do.
“I hadn’t thought about it,” he said. “I was just a squirrelly kid who liked to be active.”
Bushway, a Kish acolyte and now a World of Access instructor, is pure Southern California: casual, at home in shorts, enjoys a Mexican beer at lunch. He lost his eyesight from optic nerve atrophy in the eighth grade. But walking through school, he could still “see” columns in the hallway, even count them. He was baffled. When he met Kish in 1996, he told him about this phenomenon. Kish concluded his brain was forming a spatial image from the ambient sound reflecting off and sluicing through the columns.
“I was imaging acoustically,” Bushway said. “The brain creates images whether you send it patterns of light or patterns of sound.”
Kish worked with him to process those sounds but also taught him to use the click when the ambient sound didn’t offer enough information. Bushway was inspired by Kish’s breaking through barriers. “Wow, this guy lives his life independently,” Bushway recalled thinking. “He does all these fun activities. He could ride a bike. He likes walking and exploring neighborhoods and playing laser tag.”
Kish showed Bushway how to skateboard, using a long cane to read the road surface and curbs and clicking to spot parked cars, intersections, and turns. With the help of another instructor, Andy Griffin, who could see, they started mountain biking trails and fire roads. Griffin would lead, with zip ties around his spokes to send out a blizzard of clicks. Kish and Bushway would follow, making their own clicks to locate trees and boulders. In this sonic caravan, they could charge over roots, ruts, and rocks as speedily as most bikers—with a few more scrapes to show.
The National Federation of the Blind is neutral on Kish’s work: Spokesman Chris Danielson said many blind people tap their canes for a similar effect. Kish says the click is more effective because it is directional and doesn’t change with the surface of the ground or the angle of the cane.
In Long Beach, working with Bushway, Hirosawa was struggling to catch the fast-fleeting echo. If he stood five feet from a wall, the echo followed his click in less than 1/100 of a second. Bushway knows it’s difficult. “The hierarchy is: Visual information is the loudest, then tactile information, then acoustic information,” he explained. “So we’re asking the brain to really start paying attention to really subtle stimuli in the environment.”
Hirosawa had traveled here from Japan. It was his second trip. At home, he said, his parents locked him indoors because they were concerned for his safety. He sneaked out when he could, but the main path into town follows a river, and he fell in several times.
He and Bushway walked and crossed a busier street and turned back, aiming their clicks to the corner. The echo was sharp, almost metallic. “There is a house,” Hirosawa said. “The surface is really smooth.”
Bushway told him to take note of the unique echo so when he was walking back, he’d know to turn down that lane to reach Kish’s bungalow. “That’s a great acoustic landmark there.”
Hirosawa kept clicking, taking in the distinctiveness of the sound. The next time he left his parents’ house, he’d listen for similar spots. And he’d have sonic breadcrumbs to lead him back home.