Objectives: Reduced hearing ability has been shown to influence various aspects of daily life, such as communication, psychosocial functioning, and working life. The aim of this study is to examine the association between hearing ability in noise and both sick leave and self-reported work productivity. In addition, the relationship between hearing ability and perceived health-caused limitations at work is examined.
Methods: Data were collected at the baseline measurement of the Dutch "National Longitudinal Study on Hearing" and at each month during a subsequent period of 3 mo. Hearing ability was determined by means of the National Hearing Test, a speech-in-noise test over the Internet using digit triplets. The sample comprised 748 workers (385 with normal hearing ability and 363 with insufficient or poor hearing ability).
Results: Linear regression analyses revealed a significant adverse association between reduced hearing ability and self-reported absolute and differential productivity; for every dB signal-to-noise ratio (dB SNR) poorer hearing ability, self-rated absolute productivity for people experiencing little social support decreased by 0.054 points on a scale from 0 to 10 (b = -0.054; 95% confidence interval [CI] = -0.088 to -0.02). For people with less than three other chronic conditions, self-rated differential productivity also decreased significantly with decreasing hearing ability (no chronic conditions: b = -0.048 points/dB SNR on a scale from -10 to + 10, 95% CI = -0.094 to -0.001; one or two other chronic conditions: b = -0.035 points/dB SNR, 95% CI = -0.067 to -0.002). With adjustment for confounders, poorer hearing ability in noise furthermore significantly increased the odds for experiencing limitations (in the type or amount of work one could do) sometimes (odds ratio = 1.14; 95% CI = 1.07-1.21) and often to very often (odds ratio = 1.24; 95% CI = 1.05-1.45) in comparison with experiencing limitation seldom to never. A higher level of need for recovery among people with poorer hearing ability appeared to be one of the factors mediating the higher odds for sick leave of more than 5 days.
Conclusion: Reduced hearing ability in noise was significantly associated with a lower self-reported absolute and differential productivity in specific cases. Also, poorer hearing increased the odds for experiencing health-caused limitations in the type or amount of work one can do. The significant relationship between hearing ability and sick leave, which was found when not adjusting for confounders, could partly be explained by a higher need for recovery among people with reduced hearing ability in noise.