A research team at the University of Bath has tested how the vOICe sensory substitution device - developed by Dr Peter Meijer of The Netherlands, and Alastair Haigh and Dave Brown of Queen Mary University of London – can help transform sound signals into visual stimuli in blind and partially blind participants.
Vision-to-auditory substitution could help revolutionize the way the visually impaired are treated for this disability. Standard invasive treatments for the visually impaired such as stem cell implants, a process that includes grafting stems cells onto the eye using human amniotic membrane tissue, is challenging with some patients standing the risk of experiencing treatment failure due to the eye not being able to retain the stem cells.
So, what’s the options for restoring vision in blind and partially blind patients? Fascinating research led by Dr Michael Proulx has revealed how participants wearing a blindfold were able to respond to an eyesight test by responding to sensor information delivered via the vOICe device.
It’s fascinating to think that, without eyesight, are humans still able to experience a visual sensation? The vOICe device is deigned to gather sensor data (i.e., to capture an image) using a camera lens and converting this information into a cluster of natural sounds that are delivered directly to the participant via headphones at one soundscape per second.
The interesting mechanism behind this conversion of visual-to-audio signal is dependent on the left to right scan of an image. When the camera scans the image or a visual scene, there is a frequency to help represent this scan to feedback information on vertical axis and how bright this image is. Quite amazingly, this frequency is experienced by the user as “snapshots” of that visual scene.
Blindfolded study participant using the vOICe device. Image credits: University of Bath.
The study testing the acuity of blindfolded sighted participants with this sensory device, demonstrated a marked improvement in resolving detail about their surroundings using soundscapes upon a second attempt (i.e., being able to interpret sound stimuli whilst taking a sight test).
From this study Dr Michael Proulx stated that “This level of visual performance exceeds that of the current invasive technique for vision restoration, such as stem cell implants and retinal prostheses after extensive training.”
Studies that are carried out in a controlled environment will be far different to a real world setting, thus this has to be considered when thinking about how much this sensory device could be pushed to its limits in an enviroment with uncontrollable background noise.
There is also the consideration of confounding factors that could affect the physiological conditions of the subjects targeted to use this novel technology.
Looking at how a blind or partially blind patient can visually perceive with the aid of a sound cue is a fascinating concept with some big challenges ahead in this field of research. It will be interesting to see how the quality of output from a device such as the vOICe can be refined to completely replace sensory function that has been lost.
Miniaturizing sensor substitution devices may also be key to helping integrate this non-invasive treatment and making it more readily available for the visually impaired. Would a blind or partially blind individual be taken more to a non-invasive option that may require training, or an invasive option whereby eyesight could be completely restored?
It is possible that when considering the risks that come with invasive treatments relating to eyesight restoration, a full training program could allow target patients to become more comfortable with the use of a sensor substitution device to “see with sound”.
Haigh A. et al. How well do you see what you hear? The acuity of visual-to-auditory sensory substitution. Frontiers in Psychology. 2013;4:1-13.
University of Bath - Device offers new alternative to blind people
Ortega l, et al. Combined microfabrication and electrospinning to produce 3-D architectures for corneal repair. Acta Biomaterialia. 2013;9(3): 5511–5520.