vOICe: Helping People See with Sound

A demonstration of the vOICe experiment. Photo credit: Nic Delves-Broughton/University of Bath Source: http://www.theguardian.com/society/2014/dec/07/voice-soundscape-headsets-allow-blind-see

It seems like there is an almost constant stream of awesome new technology these days, and there has been a rather fantastic addition! A device is being researched at both the California Institute of Technology (Caltech) in the US and the University of Bath in the UK, with a very noble goal in mind; to build better vision aids for the blind.

Now it has long been known that blind people often rely on sound as a substitution for sight, with some individuals sense of hearing heightened to the point of being able to use echolocation. Well, it turns out that sound can also be designed to convey visual information, allowing people to form a kind of mental map of their environment. This is achieved by the device known as “vOICe”; a pair of smart glasses capable of translating images into sounds.

The device itself consists of a pair of dark glasses with a camera attached, all of which is connected to a computer. The system can then convert the pixels in the camera’s video feed into a soundscape that maps brightness and vertical location to an associated pitch and volume. This means that a bright cluster of pixels at the top of the frame will produce a loud sound with a high pitch, and a dark area toward the bottom will give the opposite; a quiet sound with a low pitch.

But what is really impressive about this technology is that this soundscape appears to be intuitively understood, requiring little to no training at all! In a test performed by researchers Noelle Stiles and Shinsuke Shimojo at Caltech, blind people with no experience of using the device were able to match shapes to sounds just as well as those who had been trained, with both groups performing 33% better than pure chance. In contrast, when the coding was reversed (high point = low pitch, bright pixels = quiet etc.) volunteers performed significantly worse. So how did they achieve such an intuitive system?

Well it began with Stiles and Shimojo working to understand how people naturally map sounds to other senses. Both blind and sighted volunteers were involved in the systems development, with sighted people being asked to match images to sounds, and blind volunteers being asked to do the same with textures. The pattern of choices during these trials directly shaped vOICe’s algorithm, and appeared to produce an intuitive result. This seemed to be a surprise to the researchers, as they wrote that “the result that select natural stimuli could be intuitive with sensory substitution, with or without training, was unexpected”.

This information successfully managed to get me excited, and already had me itching to learn more. It was then that I found out the research at the University of Bath further emphasised the importance of having such an intuitive system. Here the researchers claim that some users are exceeding the level of visual performance often achieved by more invasive restoration techniques, such as stem cell implants or prosthetics. While people who receive such surgery are rarely able to make out more than abstract images, some long-term users of vOICe claim to form images in their brain somewhat similar to sight, as their brains become rewired to “see” without use of their eyes.

Michael J Proulx, an associate professor at the university’s department of psychology, gave the example of a man in his 60s who had been born blind. Proulx reports that he initially thought the idea was a joke, too sci-fi to be real, but “after 1 hour of training, he was walking down the hall, avoiding obstacles, grabbing objects on a table. He was floored by how much he could do with it”. He also reports that after a few weeks of use, some people were able to achieve levels of vision of 20/250. To put that into perspective for you, a short-sighted person who removed their glasses would have a level around 20/400. That’s right, this tech could allow the completely blind to see better than those who are still partially sighted! That’s something to wrap your head around.

But slow down there with your excitement! While this technology is truly revolutionary, it is worth pointing out that there is a huge gulf between distinguishing patterns in a lab environment and using vOICe to actually observe and understand the real world. For example, we don’t know how a busy street, with an already large amount of visual and auditory information, would affect both the device’s signals and how they are interpreted. But there is no denying that this work represents and important step on the road to developing better vision aids, and given that the World Health Organisation estimates a total of 39 million blind people in the world, this technology could bring about a dramatic increase in quality of life across the globe.

But that’s not all this technology could do, as the results are challenging the concept of what being able to “see” actually means. This is illustrated by a quote from Shimojo at Caltech, where she mentions that “our research has shown that the visual cortex can be activated by sound, indicating that we don’t really need our eyes to see”. This has profound implications for the field of neuroscience, and has led to another study beginning at the University of Bath to examine exactly how much information is required for a person to “see” in this way. This could not only lead to optimisation of this technology, but to a deeper understanding of how the human brain processes sensory information.

Now I don’t know about you, but I remember when stuff like this was considered to be firmly stuck in the realm of science fiction, and the fact that such talented scientists keep bringing it closer to reality still surprises me. Combine this with an incredible rate of progress, and there really is no way of knowing what futuristic tech they’ll come up with next. This can make keeping up with it all one hell of a challenge, but fear not, my scientific friends! I shall remain here to shout about anything new that comes along.

Sources not mention in text:

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