IF YOU can hear, you probably take sound for granted. Without thinking, we swing our attention in the direction of a loud or unexpected sound - the honk of a car horn, say. Because deaf people lack access to such potentially life-saving cues, a group of researchers from the Korea Advanced Institute of Science and Technology (KAIST) in Daejeon built a pair of glasses which allows the wearer to “see” when a loud sound is made, and gives an indication of where it came from.