Brains of blind youth can rewire to sharpen hearing

The brains of people blind early in life are able to rewire to sharpen their hearing.

That's revealed in two studies on the senses, out of the University of Washington and partner universities.

"A lot of blind people are musicians, and a lot of blind people are piano tuners, and that's what kind of tipped us off," said Ione Fine, a University of Washington professor and senior author on both studies.

They found that blindness doesn't lead to hearing more sounds, rather, it can give the ability to discern small differences between each sound.

"Early blind" individuals were also better able to detect moving objects, like a car on the street, by hearing alone.

Where sighted people rely on their eyes to track things that are moving, such as cars, blind people can do so by listening. It's because, according to one of the studies, they're more able to detect the frequencies put off by moving objects.

Fine explained it this way: "There's lots of objects out there. So you have to kind of know that what you're tracking sounds — like this 'weee' or like this 'whooo' — and this study showed that it may be helping blind people track objects in the world."

She said early blind individuals are more prone to this ability because their brain is able to rewire its hearing system. It's the first study to show that blindness can result in neuroplasticity (that rewiring) in the auditory cortex.

Fine said this revelation could eventually help develop recoveries for stroke or other conditions.

"If we can understand the principles of how the brains can change the way they wire, then that could really help us with things like rehabilitation," she said. It could inform future research about the ability of the brain to change.

The two studies were published in the Proceedings of the National Academy of Sciences and the Journal of Neuroscience.