So-called "shock jocks" don't shock radio listeners all that much, according to a Strategic Radio Research survey released Monday. Only 29% of 1,014 listeners polled were offended by the "bathroom humor" used by such deejays as New York's Howard Stern. Other findings: 17% objected to jokes about sex, 40% to AIDS jokes. Southerners are more apt to be offended than people from other regions. The majority of those polled also oppose stronger Federal Communications Commission controls over language and subject matter broadcast over airwaves.