Sound: aim for ~35 dB, and hate inconsistency

Urban bedrooms sit at 60–70 dB. It's the *change* in sound that wakes you.

Rural night noise sits around 35 dB; urban baselines are 60–70 dB. WHO recommends outdoor night noise under 40 dB, with sleep effects starting around 30–35 dB indoors. Sound matters as much as, if not more than, any other factor — noise fragments sleep and raises cardiovascular risk even when you don't consciously wake.

The big issue is inconsistency: a dog getting up, a window creaking, a car passing, an air conditioner cycling. A sound machine masks these — but most people put it too loud (default 40–50 dB) and too close. The evidence for white noise itself is weak; keep it under 40 dB, especially for children.

Podcasts, TV and audiobooks running through the night are a common cognitive switch-off strategy. It's understandable — but it will never lead to your best sleep. Better: find a down-regulation method that gives you the same switch without disrupting the night.

Sources · 4

Night noise guidelines for EuropeWorld Health Organization Regional Office for Europe · 2009Recommends outdoor night noise below 40 dB (L_night) to protect health; effects begin around 30–35 dB indoors.Auditory and non-auditory effects of noise on healthBasner M, Babisch W, Davis A, et al. · 2014Night-time noise fragments sleep and raises cardiovascular risk even when people don't consciously wake.Noise as a sleep aidRiedy SM, Smith MG, Rocha S, Basner M · 2021Evidence for white/pink noise as a sleep aid is weak and low quality — it can mask inconsistent sounds, but keep it quiet.Environmental noise and sleep disturbancesHalperin D · 2014Review linking traffic and environmental noise with awakenings, sleep-stage changes and next-day effects.

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Sound: aim for ~35 dB, and hate inconsistency?

Urban bedrooms sit at 60–70 dB. It's the *change* in sound that wakes you.

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Educational summary of published research, not medical advice. Screening scores are not diagnoses. If a score is elevated or you feel unwell, talk to a clinician.