White noise machines and apps have surged in popularity, promising a better night’s sleep. But does white noise actually work, or is it just a trendy sleep aid with little scientific backing? This article delves into the research to uncover the truth about white noise and its impact on sleep.
White noise is defined as a consistent sound containing all audible frequencies played at equal intensity, creating a masking effect that can block out other disruptive noises. Think of the static hiss of an untuned radio or the whirring of a fan. The theory behind using white noise for sleep is that it helps drown out environmental sounds like traffic or barking dogs, creating a more peaceful sleep environment. Some believe it can also trigger a Pavlovian response, associating the consistent sound with sleep onset.
However, a comprehensive review of 38 scientific studies on noise as a sleep aid, published in Sleep Medicine Reviews, found limited evidence to support these claims. While some studies indicated that continuous noise may slightly reduce sleep onset latency (the time it takes to fall asleep), the evidence quality was generally poor. Furthermore, at least one study suggested that white noise might actually lead to more fragmented sleep.
Professor Mathias Basner, a psychiatry professor at the University of Pennsylvania and lead author of the review, cautions against widespread recommendation of white noise for sleep due to the lack of strong evidence and the potential for negative consequences. He expresses concern about the potential for long-term harm to the auditory system from continuous noise exposure overnight, preventing it from resting and regenerating.
Other sleep experts echo these concerns. Professor Colin Espie, a sleep medicine professor at the University of Oxford, points out that the concept of white noise as a sleep aid is limited, particularly for those struggling with racing thoughts or mental hyperactivity, which are often the root cause of sleep problems. He suggests that white noise, like other forms of monotonous stimulation, offers little benefit in addressing these core issues.
Professor Christian Cajochen, head of the Centre for Chronobiology at the University of Basel, acknowledges that white noise might be beneficial for nightshift workers needing to sleep during daytime noise. However, in relatively quiet sleep environments, he sees little benefit. Instead, he recommends evidence-based approaches like mindfulness apps and Cognitive Behavioral Therapy for Insomnia (CBT-I), which have proven effective in addressing the underlying causes of sleep difficulties.
