World Access for the Blind teaches blind people of any age, background, or ability, and it believes that anyone can learn to develop functional images of their environment to find more freedom by ‘seeing’ in a new way.

World Access for the Blind trains blind and visually impaired persons the technique of human echolocation and calls its training Flashsonar (quite like the navigation of bats). The technique allows people to navigate using tongue-clicking and by responding to the reflected sound from their surroundings. The tongue click allows the ear and brain to work together to construct a 3-D image from reflected echoes of objects.

https://worldaccessfortheblind.net