Low-level noise in open-style offices seems to result in higher levels of stress and lower task motivation, according to a new study by a Cornell University environmental psychologist.

And, surprisingly, experienced workers in these mildly noisy offices make fewer ergonomic adjustments to their workstations than do workers in quiet offices.

These findings suggest that even moderately noisy open offices might contribute significantly to health problems such as heart disease (due to elevated levels of epinephrine, a stress hormone) and musculoskeletal problems, says Gary Evans, professor of design and environmental analysis. Evans is a leading expert on environmental stress, such as noise and crowding.

The study is published in a recent issue of the Journal of Applied Psychology (Vol. 85, No. 5, pp. 779-783, 2000).

With former Cornell graduate student Dana Johnson (M.S. '99), Evans randomly assigned 40 experienced clerical workers (all female and average age 37 years) to either a quiet office or one with low-intensity office noise (including speech) for three hours.

The environmental psychologists found that the workers in the noisy office experienced significantly higher levels of stress (as measured by urinary epinephrine), made 40 percent fewer attempts to solve an unsolvable puzzle and made only half as many ergonomic adjustments to their workstations as did their colleagues in quiet offices. Typing performance, however, was not affected.

"Whereas previous studies have looked at the effects of high-intensity noise, our study is one of the few to look at low-intensity noise. Yet our findings resemble those in studies of very noisy environments in that we found that realistic, open-office noise has modest but adverse effects on physiological stress and motivation," says Evans.

Workers in the noisy offices were also much less likely to adjust their chairs, foot rests, whiteboards and document holders than workers in quiet offices. "We're not sure why this is so," Evans says. "One possible reason is that under stress, people focus in on their main task or activity. This focusing leads to less flexibility in considering alternatives during decision making, for example. Perhaps if people are working at a task and are under more stress, they become more focused on the task itself, not being as cognizant as they should be to change their posture or take a break."

Interestingly, however, the workers themselves did not report higher levels of stress in the noisy office. "But just because people fail to report that environmental conditions are negative, we can't assume that there are no adverse impacts," Evans says.

"In terms of practice, our findings are potentially important, because if worker motivation is lower under open-office noise because of its uncontrollability, various design options could be adopted. For example, when concentration is required, workers might use a quiet, enclosed room or sound-making devices that they would control. These kinds of measures might help alleviate the harmful effects of open-office noise on workers."

The study was supported, in part, by Herman Miller Co.