The impacts of noisy workplaces on productivity

Walk into many low- or middle-income country workplaces and the first thing you notice is being hit with a wall of sound. Industrial workplaces in India and China regularly expose workers to noise levels exceeding 90 decibels, a level that the US Centers for Disease Control and Prevention estimates will induce disabling hearing loss in one out of four workers exposed (Nandi and Dhatrak 2008, Zhang et al. 2015). One recent meta-analysis found that approximately half of Indian industrial workers have noise induced hearing loss (Basu et al. 2022).

While clearly a significant public health problem, this exposure may also create an economic problem. Decades of psychology research suggests that noise can impair workers’ task management skills like attention and working memory (Szalma and Hancock 2011, Matthews et al. 2000, Jones and Broadbent 1991). Therefore, workers may also be less productive in these noisy conditions.

Does noise reduce productivity?

To explore this question, I recently ran two experiments in Nairobi, Kenya (Dean 2024). In the first experiment, I recruited casual labourers who typically work in textile factories to come to a government training centre for a two-week course. During the course they learned the basics of how to operate a sewing machine and practiced their skills by making pockets. This pocket sewing task is used by the centre to evaluate potential hires because it requires all the basic key sewing skills, including sewing at specified distances, sewing in parallel, hemming, neatly backstitching, and taking corners.

Participants worked in one of two rooms during each session. The noise level varied as a diesel engine, which the centre uses to train automotive mechanics, was placed outside a randomly chosen room for each session. For ethical reasons, the noise level was much lower than what is typically experienced in factories. However, it is otherwise similar in that it has no informational content and is relatively constant.

Figure 1: Engine used in the experiment

I find that when the engine is running outside of the room, the increased noise decreased productivity by 3%. For a firm, this change in productivity is equivalent to the impact of doubling the piece rate the participants were being paid for the pockets and sufficient to make investments in noise abatement cost effective. This is particularly true given that some of the simplest and most effective forms of noise control do not require large financial investments. For example, regular maintenance of vibrating machines can prevent loose bolts or other machine parts from making egregious amounts of noise. 

Why does noise affect productivity and do workers understand the effects?

In order to understand the mechanism behind this reduced productivity, I conducted a second experiment that mirrors the first except that instead of making pockets the participants were either taking cognitive tests or a relatively pure test of effort: alternating pressing a and b on a keyboard (DellaVigna and Pope 2018). I find that the same kind of noise decreases performance on the cognitive tests but does not decrease effort. This suggests that noise affects productivity not due to mechanisms such as workers reducing effort out of resentment, but rather their impaired task management skills as hypothesised by the psychology literature. 

Finally, I assessed the degree to which our participants understood how noise was affecting their skills and productivity by offering participants the chance to pay to work in quiet while randomly varying whether they were compensated based on their performance. If participants understand they will be less productive in noisy conditions, they should be more willing to invest in having a quiet workplace as they will recoup some of the investment through increased performance pay. I find both that willingness to pay for quiet is low and that it is not higher when receiving performance pay, suggesting workers are not aware of the effects of noise and will not act to mitigate their earnings losses. 

Potential for win-win solutions

Noise is not the only workplace annoyance that can have productivity consequences. A new stream of research has shown that workers are also less productive in high heat (Garg et al. 2024, Adhvaryu et al. 2020), when they are hungry (Schofield 2020), and when the air quality is bad (Zivin and Neidell 2012, Chang et al. 2016, Adhvaryu et al. 2022). 

Taken together, this suggests a re-think in the way that policymakers, researchers and firms think about workplace hazards. Firms may be able to invest in safer and more pleasant workplaces while also raising productivity. Whether these opportunities exist and how widespread they are will take significantly more research. Afterall, most firms do not experiment with the noise level, temperature or air quality of their workplaces. But with more investigation, it may turn out that we can turn down the noise level, reduce hearing loss, and raise productivity all at the same time. 

References

Adhvaryu, A, N Kala, and A Nyshadham (2020), “The light and the heat: Productivity co-benefits of energy-saving technology,” The Review of Economics and Statistics, 102(4): 779–792. https://doi.org/10.1162/rest_a_00886.

Adhvaryu, A, N Kala, and A Nyshadham (2022), “Management and shocks to worker productivity,” Journal of Political Economy, 130(1): 1–47. https://doi.org/10.1086/717046.

Basu, S, A Aggarwal, K Dushyant, and S Garg (2022), “Occupational noise induced hearing loss in India: A systematic review and meta-analysis,” Indian Journal of Community Medicine, 47(2): 166–171. https://doi.org/10.4103/ijcm.ijcm_1267_21.

Chang, T, J Graff Zivin, T Gross, and M Neidell (2016), “The effect of pollution on worker productivity: Evidence from call-center workers in China,” NBER Working Paper Series, NBER. https://doi.org/10.1111/j.1749-6632.1963.tb13393.x.

Dean, J T (2024), “Noise, cognitive function, and worker productivity,” American Economic Journal: Applied Economics, 16(4): 322–360. https://doi.org/10.1257/app.20220532.

DellaVigna, S, and D Pope (2018), “What motivates effort? Evidence and expert forecasts,” The Review of Economic Studies, 85(2): 1029–1069. https://doi.org/10.3386/w22193.

Garg, T, M Jagnani, and E Lyons (2024), “Heat and team production: Experimental evidence from Bangladesh,” SSRN Electronic Journal. https://doi.org/10.2139/ssrn.4908494.

Jones, D M, and D E Broadbent (1991), “Human performance and noise,” in Handbook of Acoustical Measurements and Noise Control, edited by Cyril Harris, 24.1–24.24. McGraw-Hill.

Matthews, G, D R Davies, S J Westerman, and R B Stammers (2000), “Noise and irrelevant speech,” in Human Performance: Cognition, Stress and Individual Differences, 177–192. Philadelphia, PA: Psychology Press.

Nandi, S S, and S V Dhatrak (2008), “Occupational noise-induced hearing loss in India,” Indian Journal of Occupational & Environmental Medicine, 12(3): 53–56. https://doi.org/10.4103/0019.

Schofield, H (2020), “Ramadan fasting and agricultural output,” Unpublished manuscript.

Szalma, J L, and P A Hancock (2011), “Noise effects on human performance: A meta-analytic synthesis,” Psychological Bulletin, 137(4): 682–707. https://doi.org/10.1037/a0023987.

Zhang, H, N Li, Q-L Yang, W Qiu, L-L Zhu, L-Y Tao, R I Davis, N Heyer, and Y-M Zhao (2015), “Comparison of two dose-response relationship of noise exposure evaluation results with high frequency hearing loss,” Chinese Medical Journal, 128(6): 816. https://doi.org/10.4103/0366-6999.152659.

Zivin, J G, and M J Neidell (2012), “The impact of pollution on worker productivity,” American Economic Review, 102(7): 3652–3673. https://doi.org/10.1257/aer.102.7.3652.