Using Sound As An Alternative For Sight

One approach is to use sound as a stand-in for vision. In a study published in Current Biology, neuroscientists at the Hebrew University of Jerusalem used a “sensory substitution device” dubbed “the vOICe” (Oh, I See!) to enable congenitally blind patients to see using sound. The device translates visual images into brief bursts of music, which the participants then learn to decode.

Over a series of training sessions they learn, for example, that a short, loud synthesizer sound signifies a vertical line, while a longer burst equates to a horizontal one. Ascending and descending tones reflect the corresponding directions, and pitch and volume relay details about elevation and brightness. Layering these sound qualities and playing several in sequence (each burst lasts about one second) thus gradually builds an image as simple as a basic shape or as complex as a landscape.

The concept has tried and true analogs in the animal world, says Dr. Amir Amedi, the lead researcher on the study. “The idea is to replace information from a missing sense by using input from a different sense. It’s just like bats and dolphins use sounds and echolocation to ‘see’ using their ears.”

Starting with sounds for basic shapes and lines, the participants in the recent study worked their way up to being able to identify bodily forms and positions – “seeing” them in their mind even though they had never before caught sight of a human form. Remarkably, after approximately 70 hours of training, the blind participants were able to convert the sounds into visual activity in their brains, tapping into the same areas as control subjects who had seen the target images. This included a specific part of the visual cortex – the extrastriate body area (EBA) – that is specially activated when perceiving human shapes and positions.


These participants had never before been able to perceive an entire human body. They could grab a hand, touch a cheek, even wrap someone in a bear hug, but they didn’t know what a person looked like squatting down, standing on one leg, or pumping their fists in the air. Yet despite this, these individuals were able to activate a very specific area of the visual cortex just by hearing certain sounds, correctly identifying these positions.

According to Dr. Amedi, the brain is able to transfer the initial activation in the auditory cortex into the “correct” visual area of the brain. “What is going on is neuronal recycling, in the sense that the same neurons [are] doing the same task, but now with a different sensory modality.”

Source : Discover Magazine