After administering the Indian adaptation of Weinstein' s noise sensitivity scale (1988) on a population of 225 post-graduate students, a sample of 100 students, 50 of high and 50 of low noise sensitivity, was drawn at random. These Ss were then assigned on random to five high and five lore noise sensitivity groups, each having ten Ss. A multigroup design was followed to investigate the low and high intensity noises of continuous and unperiodic nature on a multiplication-subtraction task. Quantitative, qualitative and physiological energy expenditure inferred from the drop of fore-arm skin resistance, were measured. The significance of difference amongst various group means were tested by employing Duncan' s Range Test and Students t-test. Results indicated that due to adaptation, efficiency was not much affected even under high intensity noise in the case of low noise sensitivity Ss, but adaptation was not effective and efficiency was adversely affected in the case of high noise sensitivity Ss under both high as well as low intensity of noises.