Traffic noise and its impact on sleep depth measured by the odds ratio product

Abstract

Traffic noise can lead to cortical and autonomic activation, disrupt sleep and impair physical and mental restoration. We used the odds ratio product (ORP), a validated continuous measure of sleep depth based on automatic analysis of physiologic sleep data in 3-second epochs, to investigate temporal changes of sleep in response to nocturnal noise events. Seventy-two healthy participants slept for 10 nights in a laboratory, during which we measured sleep with polysomnography. In 8 nights, participants were exposed to 40, 80 or 120 road, rail and/or aircraft noise events at 45-65 dB LAS,max. Event-related change of ORP relative to pre-event baseline was analysed with linear mixed models. ORP increased during aircraft, road and rail noise, reflecting reduced sleep depth and quality, and there was a greater response to road and rail noise than to aircraft noise. The clinical relevance of event-related elevations of ORP is currently unknown, and warrants further investigation.