John Tracy, the son of actor Spencer Tracy for whom a well-known center for deaf children was named, has died. He was 82. Tracy died late Friday night at his son's home in Acton, where he had lived for the past several years, his sister, Louise Treadwell "Susie" Tracy, said in a statement Saturday. -snip Tracy had Usher Syndrome, a genetic disease that affects hearing and vision. His mother, Louise, discovered he was deaf when a slamming porch door failed to wake the sleeping 10-month-old. "The impact seemed to shake the building, but the boy slept soundly," the clinic said...