Scientists in the UK say the same sort of echolocation practiced by bats may also help people living with blindness better navigate the world. In a new study, they found that blind and sighted participants who took part in a 10-week training program were able to learn how to perform echolocation, and the blind participants largely reported that it seemed to improve their mobility and ability to live independently afterward.
Echolocation — when an animal emits sound and then detects how that sound bounces back in order to perceive solid objects around them — is readily practiced by certain species of mammals, such as (most) bats and whales. But at least some blind people have developed their own version of echolocation, possibly dating back to the 1700s. In more recent years, blind individuals such as Daniel Kish have written and talked about their own methods of echolocation, which usually involve mouth clicks.
Lore Thaler, an experimental psychologist at Durham University, has been studying human echolocation for several years now. Her past research has tried to tease out the specifics and possible benefits of echolocation. In 2019, for instance, a study by Thaler and her colleagues found that experienced clickers could detect small changes in their environment from a distance of 2 to 5 feet away.
“What made us explore it in the first place was that it is just such a fascinating skill, and that it has such great potential to help people who are blind and to investigate neuroplasticity on a more general level,” Thaler told Gizmodo in an email.
In this new research, published in PLOS One, Thaler and her team wanted to test if inexperienced people, both with and without sight, could be taught how to echolocate in a relatively short period of time and if this skill would then actually help people with blindness.
They recruited 14 sighted people and 12 people who became blind early in life for the experiment, which involved 20 training sessions conducted over 10 weeks. The volunteers were between the ages of 21 and 79, and none had regularly used echolocation in their lives beforehand (two of the blind individuals did have some experience, but everyone else had none). To validate their tests and set a benchmark, they also enlisted the help of seven people who had been practicing echolocation for at least a decade.
Overall, the team found that all of the individuals noticeably improved their performance on tests of echolocation over the 10-week period. These tests would involve situations like being able to recognise the relative location and size of nearby objects or being able to navigate through a natural environment outside of the lab without sight. These improvements didn’t seem to be influenced by the age or degree of blindness among participants. A few people even performed as well as expert echolocators on certain tasks, while some sighted people did better than some blind people.
Blind volunteers were also surveyed three months later about how the training may have affected their lives. They all reported experiencing improvements in their mobility as a result of the training, while 83% also reported feeling more independent. The findings, according to Thaler, suggest that this training can be easily adopted by many people — and that it can help blind people with everyday activities.
“These latest findings show that learning this skill positively affects blind people’s daily lives (i.e. improved mobility, independence, wellbeing). This is the first time that data was collected that directly attest to that,” Thaler said. “Furthermore, we found that both blind and sighted people can learn it, and that age is not a limiting factor.”
The results of their study are based on a small sample size, so they shouldn’t seen as conclusive proof of echolocation’s benefits. But Thaler and her team plan to keep looking at human echolocation in various ways. Currently, they’re working on a study of neuroimaging data to understand how learning the skill could change a person’s brain, while future research will study how echolocation taught early on may help children with blindness.
“We also plan to investigate how teaching and learning of this skill would scale up from the lab to professional instruction (i.e. how do people learn and benefit when they are not trained by researchers but by visual impairment professionals),” she added.