Whether they lose sight early or later in life, blind people estimate the location of many sounds more accurately than sighted individuals do, a new study finds. In lieu of visual cues, the blind typically learn to perceive subtle acoustic signals that help them navigate, concludes a research team led by neuroscientist Franco Lepore of the University of Montreal.
Most studies of sound localization in blind individuals have examined how accurately they can reach out and touch, with a hand or a cane, the source of a nearby tone.
Lepore and his coworkers studied the ability to tell whether two distant noise bursts, presented one after the other against a background of low-level noise, originated from the same or different locations. Participants included 14 individuals who had lost their vision before age 11 and 9 people who became blind after age 16. All had been blind for at least 20 years. Their blindness stemmed not from brain damage but from diseases of and injuries t