The influence of exposure to multiple indoor environmental parameters on human perception, performance and motivation

The impact of simultaneous short-term exposure to three environmental parameters (temperature,noise and air quality) on human perception and performance was studied in two identical climatechambers. Eight conditions were created exposing the subjects for 20 minutes to combinations oftwo levels of operative temperature (23,5 C and 28,0 C), two noise levels (52 dB(A) and60 dB(A)) and two pollution loads (pollution load absent, pollution load present). 56 participatingsubjects performed simulated office work (addition) and completed questionnaires concerningtheir perception of the environment and adverse symptoms in each combination of conditions.The subjects were informed of the conditions so they were able to make a conscious orunconscious choice to work more or less according to their perception of the conditions and theirattitude to them. Despite the short time allocated for performance of the addition task asignificant decrease in performance in warm noisy, warm polluted and warm noisy pollutedconditions could be demonstrated. Subjects reported a highly significant reduction in theacceptability of the indoor environment, in self-reported performance and in their ability toconcentrate in all deteriorated conditions, i.e. they tended to overestimate the negative effects ofeach factor. This was especially the case for noise.