Chapter 2 66 complaints in their work situation. The degree of hearing loss was moderate in the majority of these employees. The mixed study results might be explained by the population differences between the studies, since an association is more likely to be demonstrated when there is larger variation in the degree of hearing loss. Although it is assumed that the impact of poorer hearing on LE may be greater in noisy work environments (Kramer et al., 2006; Nachtegaal et al., 2009), we did not find a significant association between the perceived workplace noise and LE. Furthermore, no significant interaction effect was found between hearing status and perceived workplace noise in predicting hearing status. An explanation might be that – considering the OEC outcome – the vast majority of the study population is expected to be normally-hearing. Possibly, small differences between normallyhearing employees are not associated with LE, even not in noisy work environments. Another explanation might be that hearing protection was used by 65 percent of the employees under study, since hearing protection is expected to reduce the hindrance of loud noises. The interaction between hearing status and perceived workplace noise for predicting LE and NFR should be assessed in a population with higher degree of hearing loss. Some study limitations should be noted. There is a risk for selection bias, since employees voluntarily participated in this study. For example, feeling insecure about the hearing status might have been a reason to not participate in the study. Also, because there is currently no validated questionnaire available that measures LE during hearing-related job activities, we used a non-validated questionnaire. Lastly, we controlled for a broad spectrum of confounders. Nevertheless, we are not sure that we controlled for all relevant confounders since NFR is a complex construct. For example, the cognitive load of employees job might have been relevant. Considering the moderate association between hearing status and LE, the OEC is expected to inadequately predict subjective listening difficulties at the workplace at individual level. The predictive value of the OEC for high NFR is expected to be even poorer. Although the OEC is an appropriate instrument to assess employees’ ability to understand speech in noisy environments (Leensen, 2013; Rashid, 2018), the added value of occupational hearing screening for the identification of subjective listening difficulties and/or difficulties with work participation is modest. Occupational hearing screening might be valuable to rule out hearing loss as an
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