An SBD that quietly but quickly permeates a large room. It sounds like very slowly opening a new coke bottle.
Last year, when Jimmy took the newly designed SAT, he decided he would protest the Slimy Atrocious Test by eating lots of pinto bean burritos right before the test, and sabotaging the test room with a fassah every 5 minutes. Alas, the scores on that Saturday's SAT in that testing room where all below 1500 total. Jimmy was elated, but Alphonso Humphry who needed a 2100 to get into USC was less than pleased."