Like bats and dolphins, blind humans can use echolocation to find objects
New research published in the June issue of the scientific journal Hearing Research found that blind and visually humans can use echoes to locate objects.
“We wanted to determine unambiguously whether blind people, and perhaps even sighted people, can use echoes from an object to determine roughly where the object is located,” Daniel Rowan of the University of Southampton explained in a news release. “We also wanted to figure out what factors facilitate and restrict people’s abilities to use echoes for this purpose in order to know how to enhance ability in the real world.”
Other mammals, particularly bats and dolphins, use echolocation to navigate dark environments. Similar to man-made sonar devices, bats and dolphins emit sounds that bounce off nearby objects in the environment and determine the position of object by hearing the returning echoes.
Rowan’s research found humans also have the ability to use echoes to tell where objects are, although to a much lesser extent.
“Some people are better at this than others, and being blind doesn’t automatically confer good echolocation ability, though we don’t yet know why. Nevertheless, ability probably gets even better with extensive experience and feedback,” he explained.
Rowan and his colleagues found bursts of sound in a virtual auditory space — a technique used in surround audio systems to localize sound — could be used by sighted and blind human listeners to determine the right-versus-left position of an object. The farther the object was from the participants, the harder time they had determining its position.
“Furthermore, some echo-producing sounds are better for determining where an object is than others, and the best sounds for locating an object probably aren’t the same as for detecting the object or determining what, and how far away, the object is,” Rowan said.
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