Echolocation: People trained to hear like bats in a study that could help those with vision loss
It might be more commonly associated with dolphins and bats, but nature's own sonar system could be harnessed by blind people too.
Echolocation, where an animal bounces sounds off objects in their surroundings in order to navigate, may offer an alternative way for blind people to get around.
Bats, whales and dolphins are well known for their echolocation skills, and previous research has suggested some blind people can navigate in this way too, by making clicking noises with their mouths. Researchers from Durham University therefore wanted to find out how easily the visually impaired could learn this skill, and if age would have an effect.
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In a 10-week training programme, 12 blind and 14 sighted volunteers aged between 21 and 79 were taught click-based echolocation, where they were trained in discriminating the size of objects, orientation perception and virtual navigation.
By the end of the training, the volunteers had improved their ability to navigate using mouth clicks, and some individuals even performed comparably to expert echolocators who had been using mouth clicks on a daily basis for 10 years.
Encouragingly, neither age nor blindness were limiting factors in how well the participants could learn to echolocate, suggesting that the training could be used to help rehabilitate people in the early stages of vision loss.
“People who took part in our study reported that the training in click-based echolocation had a positive effect on their mobility, independence and wellbeing, attesting that the improvements we observed in the lab transcended into positive life benefits outside the lab,” said Dr Lore Thaler, who led the research.
“We are very excited about this and feel that it would make sense to provide information and training in click-based echolocation to people who may still have good functional vision, but who are expected to lose vision later in life because of progressive degenerative eye conditions.”
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While click-based echolocation is not currently taught to blind or partially sighted people as part of their rehabilitation, possibly due to perceived concerns of social stigma around making the required clicks, the results of this study indicate that people were confident making the noises in social situations. In fact, in a follow-up survey, all blind participants reported improved mobility after carrying out the training, and 83 per cent said they had better independence and wellbeing.
“I cannot think of any other work with blind participants that has had such enthusiastic feedback,” Thaler said.