Effect of hearing impairment on fatigue and annoyance caused by task-irrelevant speech: A working day simulation in an open-plan office

• In a laboratory experiment, participants performed a press review task for three hours. • Their performance was measured, along with perceived discomfort, fatigue and workload. • They were exposed to a mixture of noise and a voice at two intelligibility levels. • In addition, a hearing loss simulation (presbycusis) could be applied. • Results showed an influence of intelligibility on performance, with no effect of hearing ability. Open-plan offices are widely used in corporate settings to foster collaboration and reduce operational costs, yet noise, particularly from co-worker conversations, often disrupts employees. This disturbance may have distinct impacts on normal-hearing individuals and those experiencing the onset of presbycusis. This study investigates how mild age-related hearing loss influences cognitive performance and perceived fatigue in an open-plan office setting, with a focus on the impact of background speech intelligibility. Normal-hearing participants completed clerical tasks, including reading, note-taking, and writing, in four different auditory conditions combining two speech intelligibility levels and simulated hearing loss. Subjective assessment of workload, fatigue, and noise annoyance were collected alongside task performance metrics. Results indicated that speech intelligibility affects performance equally across both hearing conditions, suggesting that mild hearing loss does not significantly alter susceptibility to distraction in open-plan offices. Furthermore, it was observed that similar levels of speech intelligibility lead to equivalent decrease in performance, regardless of the participants’ hearing condition, whether normal or simulated mild hearing loss (early presbycusis).