Technology scans the environment and translates images into whistles and bleeps users can understand.
Using sound to help blind people to create images in their heads can prove more effective in enabling them to perform everyday activities, such as picking up a cup or even reading, than invasive surgical operations, according to groundbreaking new research.

A joint project involving a team of psychologists and computer scientists at the University of Bath is assessing how the brain can use sensory substitution to help blind and partially sighted people to “see”.

The team has been testing a technology called The vOICe – the three middle letters standing for “oh I see”. It was developed by Dr Peter Meijer, a scientist at Philips Research Laboratories in the Netherlands. It works by translating images from a camera built into a visor into highly complex “soundscapes”, a series of bleeps, whirrs and whistles that are transmitted to the user via headphones. The underlying technology has been around for more than a decade. The vOICe app, which drives the hardware, has been downloaded for free more than 100,000 times.

Research by the team at Bath suggests that some users are exceeding the level of visual performance often achieved by invasive techniques to restore vision, such as stem cell implants and retinal prostheses. This is partly because, even after surgery, many formerly blind people have such impaired vision that they are unable to make out anything more than abstract images. But it is also down to the remarkable results produced by the soundscapes. Some long-term users claim they have images in their minds that are somewhat akin to normal sight as their brains become rewired to “see” without using their eyes.

The results now being studied by Michael J Proulx, associate professor at the university’s department of psychology, and his colleague, Dave Brown, have surprised many who have conducted trials of the technology.

Proulx gave the example of a man in his 60s who had been born blind. “He thought the whole idea was a joke,” Proulx said. “After one hour of training, he was walking down the hall, avoiding obstacles, grabbing objects on a table. He was floored by how much he was able to do with it – something he had dismissed as a silly sci-fi idea.”
With the vOICe system, a camera scans a scene. Software then converts the images into the soundscapes, a series of noises transmitted to the headphones at the rate of roughly one per second. Visual information from objects to the wearer’s left and right are fed into the left and right ears respectively. Bright objects are louder and the sound frequency denotes whether an object is high up or low down in the visual field.

Users become familiar with how images sound, enabling them to identify shapes. The system works both for people who have become blind and for those born blind, who can use it to experience what vision is like for the first time.

The technology could help millions of people worldwide. While stem-cell technology might provide the literal sensation of sight some months after the operation, it is expensive and not always suitable.

According to the World Health Organisation, 40 million people in the world are blind, while another 250 million have some form of visual impairment. Age-related disorders, such as glaucoma and diabetes, mean those numbers are rising.

The technology can also scan words on a page. “Even people who are relatively early on in the learning process are already able to pick up the differences they need in order to distinguish between symbols or basic letters, in the same way you do with vision,” Proulx said. He added that, in the first couple of months after someone had received a retinal implant, they could expect to have a level of vision that was “20/800” – equivalent to being able to see the outline of things that were directly in front of them.

To put this in perspective, a short-sighted person who removed their glasses would have a level of vision that was around 20/400, meaning that they could see clearly up to a foot away. “We found that after just a week’s basic training, people were able to get to levels of 20/250,” Proulx said.

“There is a big problem with expectation,” he explained, pointing out that many blind people “want to have the vision they had before” after they receive stem-cell technology or retinal implants, with the result that they can experience severe depression when their vision is not fully restored and they are left disappointed by the results.

But this is not a problem with the vOICe system. “Their expectations going into it are incredibly low,” Proulx said. “I haven’t seen anyone experience frustration or depression, largely because they are so shocked that they are able to do so much.”

In research funded by the Engineering and Physical Sciences Research Council, Proulx and his team are examining how much information a person needs to receive in order to “see”. This has important consequences for neuroscience, but will also help to shape future applications of the technology.

Source: theguardian.com