News Summary
A new study from the University of Pennsylvania’s Perelman School of Medicine reveals that pink noise, commonly seen as a sleep aid, may actually disrupt sleep quality by reducing REM sleep. The research indicates that while it is often used to mask unwanted nighttime sounds, its use may lead to lighter sleep and increased awakenings. Additionally, earplugs were found to be more effective in preserving deep and REM sleep when faced with external noise. These findings call for further research into the sleep impacts of various noises, particularly in vulnerable populations.
Philadelphia
A recent study from the University of Pennsylvania’s Perelman School of Medicine suggests that pink noise, a widely used sleep aid, may actually disrupt sleep quality by reducing rapid eye movement (REM) sleep. This finding challenges the common belief that ambient sound machines and apps producing pink noise promote better rest.
The study, published in the journal Sleep on February 2, 2026, indicates that while many turn to pink noise to mask unwanted sounds at night, its use could come at the cost of restorative sleep. Researchers observed that pink noise, described as a continuous sound with emphasized lower frequencies akin to moderate rainfall or rustling leaves, significantly decreased the duration of REM sleep.
Impact on REM Sleep and Overall Quality
In the study involving 25 healthy adults aged 21 to 41, exposure to pink noise at 50 decibels was associated with a nearly 19-minute reduction in REM sleep per night. REM sleep is a crucial stage for memory consolidation, emotional regulation, and brain development. This reduction could have negative implications, especially for children whose brains are still developing and who spend a greater proportion of their sleep in the REM stage than adults.
Participants in the sleep laboratory also reported feeling that their sleep was lighter, experiencing more frequent awakenings, and perceiving their overall sleep quality as worse when exposed to pink noise or aircraft noise, compared to nights without any noise. The lead author of the study, Mathias Basner, MD, PhD, a professor of Sleep and Chronobiology in Psychiatry at the University of Pennsylvania, highlighted that the potential negative consequences of pink noise might outweigh any perceived benefits.
Earplugs as a More Effective Alternative
Contrasting with the effects of pink noise, the study found that earplugs were significantly more effective at protecting sleep from external disturbances like traffic noise. When participants wore earplugs while exposed to environmental noise, their deep sleep and REM sleep remained comparable to noise-free nights, and they did not experience increased wakefulness.
The research also investigated the combined effect of pink noise and environmental noise. When pink noise was played alongside aircraft noise, both deep sleep and REM sleep were substantially shorter, and individuals spent about 15 minutes longer awake. This suggests that using pink noise to mask other sounds may not provide the desired sleep protection and could, in fact, exacerbate sleep disruption.
Understanding Pink Noise and Sleep Stages
Pink noise is a type of broadband sound that filters out higher frequencies, making it sound softer and less “hissy” than white noise. It is often likened to natural, calming sounds such as steady rainfall or ocean waves. Despite its widespread use in sleep apps and sound machines, scientific evidence supporting its efficacy and safety has been limited.
During a typical night, humans cycle through various sleep stages, including light sleep, deep sleep, and REM sleep. Each stage plays a vital role in physical and mental restoration. Deep sleep is essential for physical recovery and clearing toxins from the brain, while REM sleep is crucial for cognitive functions like memory storage, emotional regulation, and motor skill learning. Disruptions to either of these stages have been linked to cognitive impairment, mood disorders, and other health issues.
Implications and Future Research
The findings from the University of Pennsylvania study challenge the prevailing assumptions about sound machines and sleep apps that utilize broadband noise. Researchers emphasize the need for more extensive studies, particularly focusing on vulnerable populations such as newborns and toddlers, the long-term effects of continuous broadband noise exposure, and the impact of different “colors” of noise and their safe levels.
The research involved a controlled sleep laboratory setting where participants, who reported no prior sleep disorders or regular use of noise for sleep, were monitored over seven nights. Their sleep stages were tracked using polysomnography, and they completed surveys and tests to assess sleep quality and alertness. The study’s rigorous methodology aimed to evaluate how pink noise affects sleep, especially when used to mask other sounds.
Frequently Asked Questions (FAQ)
What did the University of Pennsylvania study find about pink noise?
A study from the University of Pennsylvania’s Perelman School of Medicine suggests that pink noise, a widely used sleep aid, may actually disrupt sleep quality by reducing rapid eye movement (REM) sleep.
How does pink noise affect REM sleep?
In the study, exposure to pink noise at 50 decibels was associated with a nearly 19-minute reduction in REM sleep per night. REM sleep is a crucial stage for memory consolidation, emotional regulation, and brain development.
What is the importance of REM sleep?
REM sleep is important for memory consolidation, emotional regulation, and brain development. It is also the stage where most vivid dreams occur.
Are earplugs more effective than pink noise for sleep?
The study found that earplugs were significantly more effective at protecting sleep from external disturbances like traffic noise. When participants wore earplugs, their deep sleep and REM sleep remained comparable to noise-free nights.
What are the characteristics of pink noise?
Pink noise is a type of broadband sound that filters out higher frequencies, making it sound softer and less “hissy” than white noise. It is often likened to natural, calming sounds such as steady rainfall or ocean waves.
Key Features: Pink Noise vs. Earplugs for Sleep
| Feature | Pink Noise | Earplugs |
|---|---|---|
| Purpose | Often used as a sleep aid to mask unwanted sounds. | Used to block or significantly reduce external noise. |
| Impact on REM Sleep | Associated with a nearly 19-minute decrease in REM sleep per night. | Helps preserve REM sleep, comparable to noise-free nights. |
| Impact on Deep Sleep | Did not significantly cut deep sleep alone, but combined with environmental noise, it significantly shortened deep sleep. | Largely prevented the loss of deep sleep caused by environmental noise. |
| Effect on Overall Sleep Quality | Participants reported lighter sleep, more awakenings, and worse overall sleep quality. | Improved perceived sleep quality and alertness in noisy environments. |
| Mechanism | Broadband sound that filters higher frequencies to create a softer sound. | Physical barrier to sound waves. |
| Study Finding (Comparative) | May disrupt restorative sleep and interfere with recovery. | Significantly more effective in protecting sleep against external noise. |
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Author: STAFF HERE PHILADELPHIA WRITER
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