Cognitions and “Placebos” in Behavioral Research on Ambient Noise

Abstract

A first experiment, using visual and card-sorting tasks, found no effects of 100-db ambient noise per se, although cognitive variables in the testing situation affected both performance and ratings of disturbance. In two subsequent experiments some of the Ss were told that a noise was extraneous to their task of reproducing tachistoscopic patterns, and others were told that effects of the noise were being studied. Control Ss received no noise. Although group membership did not affect over-all perceptual accuracy, it did interact with other variables, indicating some influence on Ss' distribution of attention. The “relevant” noise was rated generally less disturbing, as predicted, but with greater variance in ratings; correlations with interview data suggest that some Ss had “cooperated” with E by judging the noise to be disturbing. Thus, in the absence of any other adequate “placebo” to control for cognitive factors, deceptive instructions may always be necessary in studies of ambient noise.