If you’ve been relying on pink noise to drown out traffic, barking dogs, or city sounds at night, new research suggests you might want to reach for a simpler solution: earplugs.

A study published online February 2 in the journal SLEEP reports that earplugs are more effective than pink noise in protecting sleep from nighttime environmental noise — and pink noise itself may even disrupt certain stages of sleep.

The research, led by Dr. Mathias Basner of the University of Pennsylvania, examined how different strategies hold up against intermittent nighttime noise. The team studied 25 healthy adults, average age 28, in a controlled seven-night sleep laboratory experiment. Participants were exposed to various conditions, including environmental noise events reaching 45 to 65 decibels, pink noise at 40 or 50 decibels, earplugs, and combinations of these interventions.

The results were revealing.

On nights when participants were exposed to environmental noise — think passing vehicles or other intermittent sounds — they experienced a reduction in deep sleep, also known as N3 sleep. This stage is critical for physical restoration and overall health.

Pink noise, often marketed as a soothing, steady background sound, came with its own downside. It reduced REM sleep, the stage associated with dreaming, memory consolidation, and emotional processing.

Even more surprising, adding pink noise on top of environmental noise did not meaningfully improve sleep structure. While there were minor improvements in sleep fragmentation and slight increases in deep sleep at certain sound levels, overall sleep quality worsened when pink noise was combined with environmental noise.

Earplugs, on the other hand, performed far better. They mitigated nearly all the negative effects of nighttime noise — except at the highest exposure level of 65 decibels, where their protective effect began to weaken.

Interestingly, despite measurable changes in sleep stages, nighttime noise exposure did not significantly affect participants’ morning cognitive performance, cardiovascular measures, or hearing. However, subjectively, people felt the difference. Participants reported poorer sleep quality, lower alertness, and worse mood after nights with environmental or pink noise.

Dr. Basner cautioned against assuming that all background noise is harmless.

“Our findings suggest that playing pink noise and other types of broadband noise during sleep could be harmful — especially for children whose brains are still developing and who spend much more time in REM sleep than adults,” he said in a statement.

The takeaway? While white and pink noise machines have become a popular sleep aid, this study suggests that when it comes to blocking out disruptive nighttime sounds, low-tech earplugs may be the more effective — and safer — solution.