Training the brain to turn sounds into images could be an alternative to surgical treatment for blind and partially sighted people, British researchers say.

Scientists at the University of Bath, working with European colleagues, have developed the vOICe sensory substitution device that helps blind people use sounds to build a mental image of things around them.

Writing in the journal Frontiers in Psychology, the researchers described how blindfolded study participants were able to capture an accurate mental image of an object in front of them when a wearable camera and the vOICe device converted its visual image into a cluster of natural sounds delivered directly to the participant via headphones.

The experiment suggested that even without eyesight, humans may still able to experience a visual sensation.

"This level of visual performance exceeds that of the current invasive techniques for vision restoration, such as stem cell implants and retinal prostheses after extensive training," Bath psychologist Michael Proulx said.

"Sensory substitution devices are not only an alternative, but might also be best employed in combination with such invasive techniques to train the brain to see again or for the first time," he said.