[nfb-talk] sonar for blind

[Ed Meskys]

The Growing Success of Seeing With Sound
from Spiegel

Two-and-a-half-year-old Juli merrily twirls around, holding a small white cane in her outstretched arm. Every so often, she makes a discreet clicking sound with her tongue. Doing so allows her to see with her ears, her parents say. She just needs more practice.

Four-and-a-half-year-old Frida already knows how it works. If someone holds out a pot lid at arm's length, she can locate it with a fair degree of precision. Using subtle tongue clicks, she scans the space in front of her face. "There it is!" she says. With a few more clicks, she can even determine the contours of the lid. The edge lies where the echo cuts off and she no longer hears a response.

The two girls are learning a method of echolocation known as "flash sonar," which resembles the type of active sonar used by bats. Both were born blind in Berlin, and both have parents who want to spare them from the typical life of a blind person.

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