A technological device scans a scene visually. The spatially distributed visual landscape is translated, so to speak, by the technology into spatially distributed sounds. This sound-landscape or soundscape is then sent to the blind hearer's ears. Over time, with practice, the hearer, listening to the sound, can experience it as a visual landscape, with objects in their places (where they would be seen in visual experience through the eyes) and recognizably distinct from other objects.
The research with this sound offers a new sensation paradigm, suggesting that sensations from the modal senses are not perceived in a hardwired receiver in one section of the brain, but may be created by features of the sensations not previously examined.
"The traditional view is that the brain takes data from the different sensory organs- in the case of sight, the retina- and, for each sense, processes it in separate regions to create a picture of the outside world. But that cannot explain how someone can have a visual experience from purely auditory information.
"As such, O'Regan [ J. Kevin O'Regan, a psychologist at Descartes University in Paris, France] says our definition of what it means to see needs to change. Our senses, he argues, are defined by the way the incoming information changes as we interact with the environment. If the information obeys the laws of perspective as you move forward and backward, we will experience it as "seeing"- no matter how the information is being delivered. If you have a device that preserves these laws, then you should be able to see through your ears or your skin, he says.
"If O'Regan is on the right track, we will have to reconsider long-held ideas of how the brain is organised to deal with incoming information. Traditionally, the brain is considered to be highly modular, with the occipital, temporal and parietal cortices handling inputs from the eyes, ears and from the skin and deep tissues, respectively. According to O'Regan, however, these regions may actually deal with certain types of information- shape or texture, for example- irrespective of which sense it comes from."
Bijal Trivedi, "Sensory hijack: rewiring brains to see with sound," NewScientist, 17 August 2010, issue no. 2773.