But Frida has aready become quite good at the method, her mother says. When she recently asked about an object they were passing in the city, Frida clicked a few times and answered: "Ah, a wall." When they were in a cemetery, she asked Frida to locate a rain barrel three meters away. Frida walked up to it, reached out her hand and patted the water. Another time Frida paused in front of a tree, clicking from the bottom up, tilting her head back as if she were taking a measurement. "How tall it is!" she exclaimed.
Even before the flash-sonar training, Frida had discovered the phenomenon of echoes. When she was crawling, she would slap her hands down on the floor and listen for reverberations. Later on, she made a habit of using a sharp, crow-like call to gauge her surroundings, whether in stairways, subway stations or stores. Since her training started, she prefers the tongue-clicking to the calls because it produces subtler echoes. Now other people's apartments have suddenly become exciting. "The first thing she does is check everything out," her mother says.
Ruiz, the flash-sonar trainer, was also a novice at one point. He learned the technique from Daniel Kish, a California native and pioneer in echolocation for the blind. As a young man, Kish climbed steep mountain trails alone, guided only by a walking stick and the echoes bouncing off his surroundings in response to his clicks. He learned to recognize shrubs, overhanging rocks, fences and sign posts (whose carved words he could then read with his fingers). His resourcefulness has already been documented by numerous television crews, and he goes by the nickname "Batman."
In recent years, Daniel Kish has taken on several assistants, most of whom are former students who now work as certified teachers for the blind. "So far, we have instructed 500 blind people and 5,000 teachers in 18 countries," Kish says.
Two years ago Kish spent a couple days working with then 7-year-old Lucas Murray in the southwestern British county of Dorset. Today, despite his blindness, Lucas enjoys playing basketball. The echoes tell him where the hoop is.
Other assignments have led Kish and his assistants to Mexico, France, Switzerland and Berlin. "Despite searching for a long time, we had never been able to find anyone teaching the method in Germany," says Steffen Zimmermann, Juli's father. Flash sonar is new to the country.
Before now, blind people were generally confined to the narrow circle tapped out by their white canes. But echoes expand the radius of this circle many times over. Loud clicking can yield signals from a building as far as 100 meters away. A parked car can be detected from five meters away. A large train station can be sounded out with a few good clicks in several directions. Someone well-practiced in flash sonar can locate the entrance to the tracks and the kiosks selling juice. The remote sensing technique is perfectly suited for unknown terrain.