Blind as a Batman: Study Shows Potential in Human Echolocation Techniques

Blind and visually impaired people may be able to determine the location of an object by using echolocation techniques similar to bats and dolphins, according to new research from the University of Southampton.

Researchers studying how hearing echoes could potentially help with navigation and spatial awareness found that people with good hearing but poor or absent eyesight showed the potential of using echoes to tell where objects are.

Bats and dolphins use echolocation, also known as biosonar, to navigate. They emit a call and listen for the echoes of those calls as the noise bounces off objects in the vicinity, using the echo to locate and identify objects. 

By testing both sighted and blind humans' ability to identify the right-versus-left position of an object using only their ears, researchers found that both sighted and blind people with good hearing, even if completely inexperienced with echolocation, showed the potential to use echoes to tell where objects were. But the echolocation was most effective in humans at high-frequencies; good performance was shown with sounds above 2 kilohertz, so people who are hearing-impaired were unable to effectively use echolocation.

"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," said research leader Daniel Rowan.

"We also found that our ability to use echoes to locate an object gets rapidly worse with increasing distance from the object, especially when the object is not directly facing us."

Rowan said that the research also showed that 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."

The next step is to take the findings and attempt to incorporate echolocation into training programs and assistive devices for the blind, as well as for sighted people in low-visibility situations.

The study was published in the journal Hearing Research.