Researchers have discovered that cats who are congenitally deaf experience enhanced remaining senses. The area of the brain that would normally pick up peripheral sound is rewired to pick up peripheral vision.
As a result deaf cats have an enhanced ability to observe moving objects. Dr Stephen Lomber of the Centre for Brain and Mind at the University of Ontario "The brain wants to compensate for the lost sense with enhancements that are beneficial."
Sources Nature Neuroscience Journal: Rebecca Smith Medical Editor Telegraph