The combined effects of noise and illumination on the performance efficiency of visual search and neuromotor task...

A battery of performance tests consisting of 'letter cancellation,' 'hand 'precision,' 'two-hand coordination,' and 'tweezer dexterity' were administered on 12 desk workers in an illumination chamber under six different combinations of noise and illumination made out of two levels of white noise (70 and 100 dB) and three levels of illuminations (50, 150, and 300 lx). The objective was to find out the combined effects of noise and illumination on the performance efficiency of the above tests. A 6 x 6 latin square design was followed. A three-way analysis of variance reflected significant combined effects of noise and illumination on the accuracy scores of the letter cancellation test and hand precision test and the efficiency score of the latter test. Significant separate effects of noise were, however, observable on the speed scores and efficiency scores of the letter cancellation test and that of illumination on the speed scores of this test as also the accuracy scores of the tweezer dexterity test. Studies ascertaining the effects of heat stress in combination with noise and illumination on human performance efficiency have been suggested.