Meaningful and nonmeaningful noise: Effects and aftereffects

In recent experiments in our laboratory two effects of white noise have been found: (1) With the Norinder, an arithmetic task employed by Frankenhaueser and Lundberg, involving decisions as to whether additions or subtractions are to be performed, 95 dBA noise decreased number of problems attempted for men in the morning but not for men in the afternoon or for women and (2) with COPE, a task involving a decision whether to attempt a more complex task with a greater probability of success or a less complex one with lower success probability, both noise and task-induced fatigue tended to produce choices of the less complex task, and the effects were additive. The present experiment employed two kinds of continuous noise of 95 dBA as well as a control or ambient noise condition (55 dBA), and a different arithmetic task, involving successive additions of columns of numbers, was employed. Preliminary analysis indicates that the effects of noise on this task are different from those on the Norinder. Effects on COPE were inconclusive, for reasons to be discussed.