You feel weightless as your body starts to relax, the mind quieting its incessant chatter; you are entering the sweet spot just before sleep overcomes you. It’s so close you can feel it….until BANG, you are jarred back to reality by an unsuspecting sound.
Whether it’s the sound of a partner snoring, nuances of urban living or rambunctious passengers on a flight-we have all fallen victim to noise pollution. Disruptive sounds are always frustrating-but does adding more noise really help?
White noise is defined as the combination of sounds at different frequencies, but similar intensity, with the goal of providing unrecognizable background noise that will mask unwelcome sounds. Let’s take a look at some of the evidence.
- One study looked at 62 patients spending three consecutive nights in the coronary care unit; an intensive hospital environment known for multiple disruptions from monitor alarms to staff conversations. Half of the group was exposed to white noise during a peak-noise hour of the night. Using the previously validated Pittsburgh Sleep Quality Index (PSQI) and sleep logs, the white noise group reported significantly improved sleep quality (even from their pre-hospital baseline), while the control group reported significantly worst quality from pre-hospital baseline.
- A similar study was done on 60 hospitalized cardiac patients who were randomized to either ocean sounds for the entire night, or no intervention. They found that the ocean sound group reported significantly improved sleep quality, as well as sleep depth and awakening.
- Another study looked at 18 healthy volunteers. When exposed to white noise they had a 38% reduction in sleep latency, or time it took to fall asleep. They also reported subjective improvement in sleep quality.
While the above studies are promising, there are some limitations, including small sample size, lack of randomization in the first study, as well as challenges in controlling the hospital environments. The studies all used sounds levels between 40-60 decibels (sound of loud whisper to normal conversation). It is important to note that hearing can be threatened with continuous sound over 85 decibels (a blender is about 90decibels). While this may seem obviously too loud, a few commercially available sound machines were found to produce higher than advised sound levels, especially when on max volume or positioned too close in proximity.
If sleep is a challenge for you, white noise may be worth a try. It comes in different flavors (pink, brown, ocean sounds, etc) and, thanks to phone applications, is freely accessible. My personal favorite is brown noise on a low volume. There are also free phone apps to measure sound level/decibels to ensure you are staying safe.
- Farokhnezhad Afshar P, Bahramnezhad F, Asgari P, Shiri M. Effect of white noise on sleep in patients admitted to a coronary care. J Caring Sci. 2016; 5 (2): 103-9.
- Williamson JW. The effects of ocean sounds on sleep after coronary artery bypass graft surgery. Am J Crit Care.1992; 1(1): 91–7.
- Messineo L, Taranto-Montemurro L, Sands S, Marques M, Azabarzin A, Wellman D. Broadband Sound Administration Improves Sleep Onset Latency in Healthy Subjects in a Model of Transient Insomnia. Frontiers of Neurology. 2017; (8) 718.
- Eggermont, J. Effects of long-term non-traumatic noise exposure on adult central auditory system. Hearing problems without hearing loss. Hearing Research. 2017; 352 (9) 12-22.
- Hugh S, Wolter E, Propst E, Gordon K, Cushing S, Papsin B. Infant Sleep Machines and Hazardous Sound Pressure Levels. Pediatrics. 2014;133 (4)