A South Los Angeles woman, convicted on the testimony of a blind man who recognized her voice, was sentenced by Compton Superior Court Judge Nancy Brown to eight years in prison for robbery. Oran Burdette, about 40, was found guilty of robbing Willie Petty, 58, a blues guitarist blinded in a 1969 car accident. Deputy Dist. Atty. Robert Ernenwein said the woman went to Petty's apartment Oct. 16, asked to use the telephone, then struck him in the chest with a cane. When he could not give her money, the prosecutor said, she fled with his radio. After an officer spotted her on the street with a cane, he took her to Petty, who identified her by her voice.