Environmental Noise and Sleep Disturbance: Night-to-Night Variability of Sleep/Wake Pattern

Abstract

Actigraphy is useful to assess sleep pattern of subjects for several days to several weeks, and collected sleep data is usually averaged out to know the general sleep pattern of each individual. However, intra-individual variability should be considered when assessing sleep patterns, with regard to the phenomenon of daily fluctuation. The aim of this study was to explore whether the mean sleep indices reflect intra-individual variability with regard to environmental noise. Indoor noise and sleep pattern were collected over 5 days, among 22 citizens of Ulsan Metropolitan city. We observed an association between environmental noise indices and various sleep indices such as sleep efficiency, number of awakenings, or fragmentation indices when we analyzed the data of 108 nights from 22 subjects. However, the significances were weakened when we analyzed noise and sleep/wake pattern after averaging out. In conclusion, we observed that the sleep/wake pattern over several days to weeks should not be averaged out when studied in relation with variable physiological phenomena, such as night-to-night variability.

Keywords

• Insomnia
• Noise
• Sleep
• Actigraphy