Have you ever been at a street corner with audible traffic lights? The lights buzz or beep when it is safe to cross the street. These sounds are designed to help a blind person negotiate traffic. But do they work?

I asked this question of a friend of mine who is blind. She told me that, in many circumstances, audible traffic signals are more of a hindrance than a help. This surprised me until I realized how different her street-crossing strategy was from my own. I depend mostly on my vision to decide when it's safe to cross the street, but my blind friend depends upon her hearing. The buzzing and beeping from the traffic signals make it hard for her to hear the oncoming cars. What's more, many blind people use the echoes bouncing off objects to help them navigate, and beeping traffic signals create confusing echoes. Although the designers of these traffic signals had the best of intentions, they may have assumed that they could imagine being blind by simply closing their eyes. They may not have realized that a blind person develops very different strategies to get around.

As I mentioned in the last post, my blind friend may take advantage of different sets of neuronal connections in her brain. In all of us, neurons from the touch and hearing systems connect with neurons in the visual cortex. These connections may be weak and ineffective in a sighted person but may be strong in someone who is blind. Perhaps this explains why my friend takes in auditory information so much faster than I do. She listens to speeded-up recordings of books in which the words are spoken too quickly for me to follow.

While there are very great differences in the way a sighted and blind person take in information, there are also differences, often less obvious, among sighted people. In Harper Lee's novel, To Kill A Mockingbird, Atticus Finch states, "You never really understand a person until you consider things from his point of view." I take this quote to heart for I am a teacher and to teach better I must try to see the world through my students' eyes. This has led to all sorts of stories which I will tell over the next several weeks.

About the Author

Susan Barry by Rosalie Winard

Susan R. Barry, Ph.D., is a professor of neurobiology in the Department of Biological Sciences at Mount Holyoke College and the author of Fixing My Gaze (June, 2009).

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