Common sleep aid used by millions actually worsens sleep quality, study finds

Millions of people rely on a sleeping pill to get their nightly Z’s, but research shows that commonly used noisy machines do more harm than good.

While many people use the constant buzz of pink noise to drown out background noise and aid sleep, one study found that adding pink noise to a noisy environment had a counterproductive effect.

Researchers at the University of Pennsylvania Perelman School of Medicine found that healthy adults who listened to pink noise, a deep, steady sound similar to rain or waterfall, lost 19 minutes of sleep during a crucial part of the cycle.

Pink noise, like the popular white noise, is a type of broadband noise characterized by continuous, uniform, static signals covering a wide range of audible frequencies.

Most of the 25 adults in the study reported feeling like their sleep was lighter, more frequently interrupted, and of poorer overall quality after nights exposed to pink noise. When pink noise was combined with aircraft noise, they found the combination of the two to be the most disruptive condition of all.

More than 16 percent of Americans – or about 53 million people – use noise machines to fall asleep each night, and three Millions of hours of white noise are streamed daily on Spotify alone, with the best noise videos on YouTube collecting over 700 million views.

Disruption of deep sleep, the period of the sleep cycle when the brain eliminates toxins and consolidates memories, and REM sleep, the dreaming phase, are associated with higher rates of depression, anxiety, injuries and accidents, Parkinson’s disease, and loss of productivity.

Sleep researchers at the University of Pennsylvania found that exposure to aircraft noise costs healthy adults about 20 minutes of REM and deep sleep per night (stock)

Twenty-five healthy adults aged 21 to 41 participated in a sleep study, published in the journal Sleep, in which they slept in a laboratory for eight hours a night for seven consecutive nights. None were regular users of sound devices or suffered from sleep disorders.

The researchers tested their sleep under a variety of conditions, including exposure to airplane noise, pink noise, and a combination of the two, as well as exposure to airplane noise while wearing earplugs.

Each morning, participants completed tests and surveys to measure sleep quality, alertness and health effects.

When exposed only to aircraft noise, people reported their sleep was lighter and more fragmented, and they rated their overall sleep quality as worse than on quiet nights.

Similarly, pink noise alone has led to reports of poorer sleep quality.

Notably, the combination of airplanes and pink noise was judged by participants to be the worst condition.

They rated their sleep as significantly lighter, reported waking up more frequently, and gave it the lowest overall quality rating.

Meanwhile, nights with airplane noise and the use of earplugs were viewed much more positively. Participants reported that the earplugs effectively dampened disruptive sounds, making their sleep deeper, less interrupted, and almost as pleasant as a quiet, restful night without background noise.

The impact of different noise conditions on deep sleep (N3). CTRL (quiet baseline, gray) is compared to EN (airplane noise, blue), EN+NP40 (airplane plus pink noise at 40 decibels, pink), EN+PN50 (airplane plus pink noise at 50 decibels, purple), and EN+EP (airplane noise with earplugs, green). Airplane noise significantly reduces deep sleep, an effect made worse when combined with pink noise but prevented by earplugs

The impact of different noise conditions on REM sleep. Pink noise, particularly at 50 decibels (purple), significantly reduces REM sleep, an effect distinct from the disruption of deep sleep caused by aircraft noise alone (blue in Figure D)

These subjective reports were strongly supported by the objective laboratory data. Exposure to aircraft noise alone reduced deep, restorative sleep by about 23 minutes per night.

Although pink noise did not have a significant impact on deep sleep, it had a detrimental effect on REM sleep, reducing it by almost 19 minutes.

The combination of airplane noise and pink noise was particularly harmful, significantly reducing deep and REM sleep while increasing wake time by 15 minutes. WEARING earplugs, however, has proven to be very effective in protecting yourself from noise.

It largely prevented the loss of deep sleep caused by aircraft noise, demonstrating that it is the most reliable method of protecting sleep from disruptive noise pollution.

Lead study author and sleep expert Dr Mathias Basner said: “Overall, our findings caution against the use of broadband noise, particularly for newborns and toddlers, and indicate that we need more research on vulnerable populations, on long-term use, on the different colors of broadband noise, and on safe broadband noise levels in relation to sleep.”

Poor sleep directly harms physical health by weakening the immune system and increasing the risk of heart disease, diabetes and obesity.

During deep sleep, the brain eliminates toxins linked to neurodegenerative diseases such as Alzheimer’s disease. Losing this step disrupts a vital restoration process.

Mentally, poor sleep impairs cognitive functions, impairing memory, concentration and judgment, and destabilizes emotional regulation, increasing vulnerability to stress, anxiety and depression.

When sleep is disrupted by environmental factors like noise, the damage is compounded if the intended solution backfires.

This means that in seeking relief, individuals may unknowingly deprive themselves of phases of sleep most essential to brain restoration and long-term health, thereby turning a common coping strategy into a contributing factor to life-threatening health problems.