Noise Pollution: How Does It Affect Sleep

How Can Noise Affect the Body During Sleep?

The cardiovascular effects of noise extend beyond whether someone finds a sound annoying. In a randomized study published in the European Heart Journal in 2013, 75 healthy volunteers experienced nights with background noise alone or recorded aircraft sounds. Researchers found poorer sleep quality, increased morning adrenaline and evidence of impaired endothelial function—the ability of the blood vessel lining to help vessels widen. [Schmidt and colleagues](https://pubmed.ncbi.nlm.nih.gov/23821397/).

These findings support a biological explanation for the link between environmental noise and cardiovascular health: sound exposure during sleep can stimulate the body's stress system while interfering with normal vascular regulation. However, an overnight change in a laboratory measurement is different from a diagnosed cardiovascular disease. The experiment helps explain a possible mechanism; it cannot establish that one noisy night causes lasting heart damage.

What Does the Recent Traffic Noise Study Show?

The study reported by the European Society of Cardiology in February 2026 involved 74 healthy adults. Each experienced a control night and nights with 30 or 60 recorded traffic noise events. Researchers assessed flow-mediated dilation, which measures how an artery widens when blood flow increases. Dilation was lower after the noise-exposure nights, and participants reported worse sleep. [European Society of Cardiology study report](https://www.escardio.org/news/press/press-releases/new-research/).

Having participants experience each condition helps reduce differences between people as an explanation for the results. Nevertheless, this was a short experiment involving healthy volunteers. Its findings support an immediate physiological effect, but cannot quantify lifetime cardiovascular risk or establish whether reducing bedroom noise prevents heart attacks.

What Noise Levels Does WHO Recommend Reducing?

WHO's environmental noise guidelines distinguish overall exposure from nighttime exposure because sleep is particularly sensitive to disturbance. Lden is a long-term day-evening-night measure that gives extra weight to evening and nighttime sound; Lnight represents average nighttime exposure. These environmental exposure indicators are different from a single sound reading beside a bed. They guide population protection rather than define a sharp boundary between safety and harm. [WHO environmental noise guidelines](https://iris.who.int/bitstream/handle/10665/279952/9789289053563-eng.pdf).

Reducing exposure requires attention to both the sound source and the building receiving it. WHO identifies approaches including quieter sources, operating-time restrictions, sound barriers, building insulation and planning controls. This makes neighborhood design and housing quality relevant to prevention: residents may have limited control over traffic outside their windows. [WHO guidance on environmental noise interventions](https://cdn.who.int/media/docs/default-source/who-compendium-on-health-and-environment/who_compendium_noise_01042022.pdf).