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Does noise affect your sleep?

By Ilia Usatov · November 2026 · 5 min read

Yes. Night-time traffic noise is linked to disturbed sleep, which is why the World Health Organization sets separate night limits for roads, railways and aircraft. Here is what those limits are and what they mean for your bedroom.

The WHO night limits

In its 2018 Environmental Noise Guidelines for the European Region, the WHO strongly recommends keeping average night-time noise below these levels:

Above these levels, the WHO links the noise to adverse effects on sleep. Its earlier Night Noise Guidelines (2009) set 40 dB as the overall night target for health.

What L_night means

These numbers aren’t the level in your bedroom. L_night is an average over the eight night hours across a whole year, measured outside, at the front of the building. Inside, with windows closed, the level is lower. With a window open, much of the outside noise comes in.

An average also hides peaks: a night with a quiet average can still include a few loud trucks or a passing train.

How many people are affected

A 2022 review of the research behind the guidelines found that the link between noise level and sleep disturbance held up for all three kinds of traffic. A summary of the WHO work reports that at 40 dB of aircraft noise, about 11% of people are highly sleep-disturbed.

What you can do

• Pick the quiet side. If you can, sleep in the room facing away from the road or railway.
• Close the window at the loudest hours, and air the room before bed instead.
• Try earplugs. They are cheap, and you can tell within a few nights whether they help.
• Measure before you buy anything. Compare your rooms at night with a meter. It tells you which room is quieter and whether a fix made a difference.

Sources

1. WHO Regional Office for Europe. Environmental Noise Guidelines for the European Region. Copenhagen, 2018.
2. WHO Regional Office for Europe. Night Noise Guidelines for Europe. Copenhagen, 2009.
3. Systematic review update on environmental noise and sleep, 2022. PubMed Central, PMC9272916.
4. Queen Mary University of London. Reduce traffic noise to prevent heart disease (summary of the 2018 WHO guidelines).

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