Echolocation can help those with vision loss – study

Blind people are able to better complete various practical and navigation tasks with the help of echolocation, new research suggests.

Echolocation occurs when an animal emits a sound that bounces off objects in the environment, returning echoes that provide information about the surrounding space.

While the technique is well known in whales and bats, previous research has also indicated some blind people may use click-based echolocation to judge spaces and improve their navigation skills.

A team of researchers, led by Dr Lore Thaler, of Durham University, looked into the factors that determine how people learn this skill.

Over the course of a 10-week training programme, the team investigated how blindness and age affect learning of click-based echolocation, and how learning this skill affects the daily life of people who are blind.

Blind and sighted participants aged between 21 and 79 took part in 20 two-to-three-hour training sessions over the study period.

Blind participants also took part in a three-month follow-up survey assessing the effects of the training on their daily life.

Researchers found that both sighted and blind people improved considerably on all measures, and in some cases performed comparatively with expert echolocators at the end of training.

In some cases sighted people even performed better than those who were blind.

The study also found that neither age nor blindness was a limiting factor in participants’ rate of learning or in their ability to apply their echolocation skills to novel, untrained tasks.

Furthermore, in the follow-up survey, all participants who were blind reported improved mobility, and 83% reported better independence and wellbeing.

Researchers say that overall the results suggest the ability to learn click-based echolocation is not strongly limited by age or level of vision.

This has positive implications for the rehabilitation of people with vision loss or in the early stages of progressive vision loss, they say.

Dr Thaler said: “I cannot think of any other work with blind participants that has had such enthusiastic feedback.

“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.

“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.”

Click-based echolocation is currently not taught as part of mobility training and rehabilitation for blind people.

And experts say there is also the possibility that some people are reluctant to use it due to a perceived stigma around making the required clicks in social environments.

Despite this, the results indicate that blind people who use echolocation, and people new to echolocation, are confident about using it in social situations, researchers say.

The study, published in the journal PLOS One, was funded by a grant from the Biotechnology and Biological Sciences Research Council United Kingdom, and a grant from the Network for Social Change.