Seeing through sound comes naturally to animals like bats and dolphins, and even to a few remarkable humans for whom seeing through eyes was not an option. Now, for those looking to learn echolocation, researchers are developing a web app that can help hone your hearing.
Learning to echolocate can allow visually impaired people, even those who are fully blind, to be more independent and improve their quality of life (scroll down to watch a video of 'batman' Daniel Kish, who has been blind since infancy, using echolocation to navigate).
But audiologist Daniel Rowan of the University of Southampton and his colleagues have found that many people who are not visually impaired are also interested in learning to echolocate, inspiring them to create an app that would both teach basic echolocation skills and further research to improve the quality of life for visually impaired people. The app is slated to be released later this year.
"Even sighted people can tell whether an object is to the right or left only from listening to the sounds," Rowan said in an email.
The app would help people to boost their listening skills by training them to recognize the locational information hidden within echo-stimulating sounds such as footsteps, finger clicking, and speech.
"The initial purpose is simply to allow the public to have a go at the experiments we've been doing, since there's been a lot of interest in our work," said Rowan.
Rowan and his colleagues hope that the app will also raise awareness for their research, which aims to improve quality of life for visually impaired people. In a study published last week in Hearing Research, they showed that the ability to hear high-frequency sounds is key for successful echolocation.
They determined that listening to high-frequency sounds is critical to successful echolocation by playing recordings of echoes to people who are able to both hear and see, and then asking them whether it sounded like the object was on the right or the left when the sound was recorded. With an unaltered recording, most people are able to do this even if they do not know how to echolocate. However, Rowan and his colleagues manipulated the recordings in several different ways to see how the changes affected the participants' ability to locate the object. They found that without the ability to hear high frequencies in both ears, the participants were able to do this much less successfully.
"This should therefore be taken into account when blind people have hearing problems," Rowan said. "Current hearing aids probably don't amplify enough the very high frequencies echolocating people may need to hear and might also mess up the subtle aspects of the sounds important for localizing objects."
Eventually, Rowan hopes to use the web app to conduct experiments similar to this on a larger scale by involving the general public. This would give the researchers a more complete picture of how to optimize hearing for echolocation.
"We hope this work will lead to better hearing aids for blind people," he said.