Ultrasonic speakers let people who are blind read Braille in mid-air

People who are blind can read Braille in mid-air using their hands thanks to a grid of speakers that emit ultrasound waves. The device creates points in the air that are similar to the dots that form Braille characters.

“On the skin this feels like a gentle breeze of air,” says Viktorija Paneva at the University of Bayreuth in Germany. The mid-air dots are perceptible on a person’s palm when they hold their hand up about 20 centimetres from the…