Can deaf people hear with their skin? Can blind people see with their tongue?

Meet Dr David Eagleman. He is a Neuroscientist, Author and Science communicator. And he has made a vibratory vest that lets the deaf people hear just by wearing it. 

Now, this sounds like some kind of futuristic technology that only Tony Stark would possess but believe me David Eagleman is real and his works are as well. In fact, his multimillion-dollar company, Neosensory, develops sensory devices for such differently-abled individuals. And soon they will develop gadgets for blind people as well with which they can easily see.

But how is such magic possible? The principle behind this is very simple. Our brain contains 86 billion neurons and each neuron has 10,000 connections. The major function of the brain is to take sensory information as electrical signals and process them into the meaning of the world around us. And we might have heard that there are different parts of the brain associated with different sensory functions such as the visual cortex with vision, somatosensory cortex with touch, auditory cortex for sound and olfactory cortex for smell. But research shows that this division isn't strictly followed. 

It means there is nothing special about the neurons present in the visual cortex than in the auditory cortex. Both neurons are the same, it only depends on the connection of neurons and how they process the incoming electrical signals. And the connection isn't static, it changes as necessary. For eg. For a blind person, the neurons in the visual cortex rearrange themselves to process more auditory signals because they aren't getting any visual information. So over time, there are greater numbers of neurons responsible for processing sound which leads to blind people having excellent sound perception abilities. Many blind people have even learned echolocation just like bats to navigate through their day to day life. This is all thanks to the addition of neurons of their visual cortex to process incoming sound signals.

The brain is a black box. It doesn't care whether the electrochemical signal comes from the eye or ear or tongue or nose. All it cares about is what to do with that signal, how to generate patterns and how to assign meaning to it.

The technology developed by the team led by David Eagleman, the vibratory Vest, works on the same principle.  The vest has several motors which take the incoming sound and convert it into vibrations on the skin. Then such vibrations are picked up by the human body and transferred to the brain. So a human can now feel or hear the sound with their skin.

But can this technology allow deaf people to understand complex sounds like human language? 

To test this, scientists have deaf people train with this vest for 4 days, two hours a day, and on the fifth day, they were able to understand basic words. Now he isn't understanding those words consciously because patterns are too complex. It is his brain that is assigning proper meaning to those signals. And David believes, after wearing it for 3 months, he will have a direct perceptual understanding of hearing.

Another device that exhibits this phenomenon is the Brain Port vision device which was developed by Paul Bach-y-Rita. It is a non-surgical visual prosthetic that translates information from a digital video camera to the user's tongue, using gentle electrical stimulation. With training, totally blind people learn to interpret the images on their own to use them as information about the scene in front of them. Past users have used the device to read words, play games, build snowmen and recognize the holds while rock climbing.

These gadgets have their applications not only in aiding differently-abled people but also in enhancing the perception of normal humans. For example, for drone pilots wearing the vest,  the data of the drone-like pitch, yaw, roll, Orientation and heading, are directed to the vest and let them feel exactly what the drone is experiencing. This lets them pilot the drone more effectively and in adverse weather conditions as well. For astronauts, this vest can let them feel the data about the health of the international space station in real-time rather than checking the ship with normal human senses. Moreover, this vest can let us have access to the invisible states of your own health like your sugar level, blood pressure, microbiome and so on. Being able to see in the ultraviolet or being able to see 360 degrees is also another of its applications. And there are many more applications.

The idea of Sensory substitution was already introduced in the 1980s but sensory augmentation is a relatively new concept. Active work in this direction is being conducted by many researchers and scientists. The field of sensory substitution and sensory augmentation has unlimited possibilities and can be very useful just as long as it doesn't add another source of constant data constantly competing for our attention.