Echolocation is the ability for animals to sense objects around them using sound. Bats and dolphins use the technique to navigate and communicate, and humans have primarily used it through technologies such as sonar and ultrasound. But it is only recently the blind have used the technique, also known as ‘acoustic way finding’ or ‘flash sonar’.
By interpreting the sound waves reflected by nearby objects, a person trained to navigate by echolocation can identify the location and sometimes size of nearby objects, and use this information to steer around obstacles and travel from place to place.
Perhaps the most astonishing case of human echolocation is that of Ben Underwood. Ben lost both of his eyes to cancer when he was three years old. Using echolocation, Ben was able to lead an extraordinarily independent life, as the video illustrates.
Tragically, Ben died in 2009 after a recurrence of the cancer which robbed him of his sight. Ben’s legacy lives on through the work of Daniel Kish (featured above) who teaches people like Lucas (below) to ‘see’ with their ears.