Annoyance reactions caused by exposure to noise consisting of clearly defined noise events in a steady background have been studied. The noise resembled that of heavy vehicles passing at a short distance or aircraft flyover near an airport. With all other parameters kept constant, the annoyance experienced by the test subjects seems to be highly dependent on the time between each single noise event. Interevent intervals of the order of 2 to 5 rain seem to be the least annoying. The results from this experiment have been combined with a previously published threshold theory to make a new model for assessing the annoyance caused by typical community noise.