EFFECTS OF MODERATE INTENSITY NOISE ON THE BAKAN VIGILANCE TASK

Most studies of vigilance show noise effects only above 95 db SPL, but some suggest that tasks with possible involvement of subvocal speech may be more vulnerable. The present 4 experiments examined the effects of moderate intensity (85 db or lower) noise on visual versions of the Bakan vigilance task, which were given to a total of 64 20-56 yr old paid female Ss. Digit sequences were observed for particular target groupings of 3 odd (Exps I and II) or odd-even-odd (Exps III and IV) digits. All 4 experiments showed either a decrease in targets detected or a decrease in total responses (including false alarms). Exps III and IV used grouped presentation of stimuli to confirm whether the impairments were due to changed use of subvocal speech, but no support was found for any of the competing current suggestions on this point. The main implication is, therefore, that noise may produce impairment at levels lower than previously thought. (7 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.