How Daytime Noise Can Affect Sleep
The noisier your work environment is during the day, the greater the chance that you won’t sleep well at night. This finding comes from a study from National Cheng Kung University in Taiwan that looked at the effect of noise on 40 hospital cafeteria workers. The researchers compared the effects of working for eight hours in a noisy environment with those experienced by the same workers when they put in a full day’s work in quieter areas. The investigators reported that the more noise the employees encountered at work, the higher their blood pressure and levels of the stress-hormone cortisol. They also found that the workers sleep suffered in the aftermath of putting in eight-hour shifts in a noisy environment: their total time asleep was lower than it was when they were assigned to quieter areas. Their slow-wave sleep – the deepest stage of non-REM sleep – was reduced after a noisy day at work. Noise levels in the cafeteria averaged between 72 decibels (about the sound of a vacuum cleaner running) and 86 decibels (similar to the sound of a diesel truck traveling at 40 miles per hour) compared to 67 decibels (a bit louder than the sound of background music) to 72 decibels elsewhere in the hospital.
My take? Both intermittent loud noises and constant low-level noise can lead to health problems. Acute loud noises can damage hearing, interfere with sleep, raise blood pressure and stress levels and cause headaches. We also know that constant low-level noise can increase levels of the stress hormone cortisol, and heart attack risk is higher among people exposed to chronic noise. Under those circumstances, noise-cancelling headphones might help mitigate the health effects of spending time in a noisy environment.
Cheng-Yu Lin et al, “Will daytime occupational noise exposures induce nighttime sleep disturbance?” Sleep Medicine, June 6, 2018, DOI: doi.org/10.1016/j.sleep.2018.05.025
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