The effects of white noise on sleep and duration in individuals living in a high noise environment in New York City.

INTRODUCTION

Undisturbed sleep has been shown to be important for both health and quality of life (Medic et al. [7]). The World Health Organization estimates that nearly 25% of the population suffers from disturbed sleep due to environmental noise (Health TWECfEa, [2]). Sleep disturbance associated with elevated noise levels is particularly prevalent in metropolitan areas. Our study tested the hypothesis that white noise would improve sleep in New Yorkers complaining of sleep difficulty due to elevated sound levels.

METHODS

Ten adult participants were included in this study. All participants were recruited from a New York City based sleep clinic. Inclusion criteria was based on the presence of sleep disturbance and the reporting of high levels of environmental noise in participants' sleep location. The study was conducted using a within-subject, ABA design, with baseline, treatment phase, followed by another baseline (washout) period. Each phase lasted one-week, during which noise level and sleep were assessed. The treatment consisted of the application of a white noise device (Dohm Classic by Marpac, LLC) in the participants' bedroom. Sleep parameters were measured subjectively using the Consensus Sleep Diary (Carney et al. [15]), and objectively using a Motionlogger Actigraph.

RESULTS

Paired sample t-tests were conducted to evaluate the hypothesis that white noise improves sleep in a high noise environment. Significance was found on the variables WASO, as measured by actigraphy, t(9) = 3.438, p = 0.007 and sleep latency as measured by sleep diary, t(9) = 2.947, p = 0.016. There was a trend toward significance on the number of awakenings during the night, as measured by sleep diary, t(9) = 2.622, p = 0.028 (Holm's sequential correction of p-value required a value of <0.01 to find significance on this comparison) and sleep efficiency (actigraph), t(9) = -2.121, p = 0.063.

CONCLUSION

Our data show that white noise significantly improved sleep based on subjective and objective measurements in subjects complaining of difficulty sleeping due to high levels of environmental noise. This suggests that the application of white noise may be an effective tool in helping to improve sleep in those settings.