Does anyone know what the loudest sound on earth is? No, it is not a million jet planes taking off at the same time, right overhead. No, it is not the detonation of the most powerful and devestating bomb invented by man. The loudest sound on earth is Elvis, Molly, and their Dad SNORING at 4 in the morning while I am trying to catch some beauty rest! THAT, my friends, is the loudest sound on earth. In stereo.