For better output, turn down the volume

Meena Thiruvengadam | Dec 02, 2020

Many people working from home have become perhaps acutely aware of noise in and around their environments—and in many places in the world, such ambient noise is increasing. 

The European Union has taken steps to restrict noise pollution. And there may be a compelling economic incentive for doing so: increased productivity. 

To better understand how noise affects productivity and cognitive function, Chicago Booth’s Joshua Dean conducted two randomized experiments in Kenya. In one, he selected 128 people to participate in a 10-day sewing course outside Nairobi, recruiting day laborers who were waiting for work at the gates of local textile factories.

Sewing can be done independently and doesn’t require people to communicate with each other. Yet Dean wondered if noise could still disrupt key tasks that require strong cognitive functions, such as sewing in a straight line or moving fabric through a machine with both hands.

While participants sewed pockets, Dean randomly exposed them to noise. The study participants were assigned a randomly generated schedule that had them sometimes working in a quiet room and other times near a car engine that was otherwise used for auto-mechanic training classes. Dean manipulated the level of noise exposure, staying well below the amount that would cause hearing loss. 

Participants working in the noisy room sewed 3 percent fewer pockets compared with those stationed in quieter settings, he finds. Productivity declined 5 percent for every 10-decibel increase in (or perceived doubling of) noise. In a second experiment, involving a similar group of people, Dean confirms that the noise specifically affected tasks that involve cognitive function.  

Workers don’t fully understand how noisy environments affect them, the research demonstrates. Participants were willing to give up only a small fraction of their pay for a quieter, more productive environment. If workers don’t understand how much noise is costing them, it seems unlikely they’ll take steps to mitigate the effects of noise. 

Dean’s research suggests noise levels not only meaningfully reduce productivity but also may have serious economic costs, particularly for poor people. A growing literature argues that various things associated with poverty—such as the amount of sleep people get, the temperatures to which they’re exposed, and the amount they worry about money—can impair task-management skills, he says, adding that environments associated with poverty tend to be especially noisy.

Such environments can hurt poor people’s ability to be productive and have serious consequences, Dean’s research suggests. “Future research,” he writes, “should provide estimates of these costs and how policies can be designed that account for these cognitive constraints.”