Blind people could use echolocation to navigate, study 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 used in the animal kingdom by species such as whales or bats, previous research has also indicated that some blind people may use click-based echolocation to judge spaces and improve their navigation skills.

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

The study involved blind and sighted participants between 21 and 79 years of age who trained over the course of 10 weeks. Blind participants also took part in a three-month follow-up survey assessing the effects of the training on their daily life.

Both sighted and blind people improved considerably on all measures and in some cases performed comparatively to expert echolocators at the end of training.

Neither age nor blindness were found to be a limiting factor in participants’ rate of learning or in their ability to apply their echolocation skills to novel, untrained tasks.

In the follow-up survey, all blind participants reported improved mobility and 83 per cent reported better independence and wellbeing.

Dr Lore Thaler, of Durham University, said the results suggest that 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.

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

Currently, click-based echolocation is not taught as part of mobility training and rehabilitation for blind people. There is also the possibility that some people are reluctant to use click-based echolocation due to a perceived stigma around making the required clicks in social environments.

However, the results of this study also indicated that blind people who use echolocation, as well as people new to echolocation, are confident about using it in social situations.

Researchers have previously developed a hat fitted with ultrasonic sensors that provide blind people with the sense of proximity to physical objects to help them navigate interiors.