← All articles
Singaporecooling weighted blanketweighted blanketcooling blanketsleep hygiene Singaporenoise and sleep By JJ · 29 Oct 2026 · 6 min read

Drowning Out HDB Noise With a Sound Machine? Pink Noise Cost Nearly 19 Minutes of REM

Drowning out HDB neighbours or traffic with a sound machine? A University of Pennsylvania sleep lab found pink noise at 50 decibels cut REM sleep by nearly 19 minutes a night, while simple foam earplugs blocked most of the damage from outside noise.

The short answer: masking sound is not the same as protecting sleep. In this study, earplugs did the protecting, and the "sleep sound" took something away.

Here is what the numbers show, and what they mean for light sleepers in Singapore and anywhere else.

How common is night noise as a sleep problem?

Very common, and it is not only a Singapore story.

In Europe, more than 20% of people are exposed to transport noise above EU reporting thresholds, according to the European Environment Agency's 2025 report. Road traffic alone exposes about 92 million people. The agency estimates that about 4.6 million Europeans suffer severe sleep disturbance from long-term transport noise.

The World Health Organization's 2018 guidelines set lower night limits than EU rules. It strongly recommends keeping average night noise below 45 dB for road traffic, 44 dB for railways and 40 dB for aircraft.

Singapore has its own version. In HDB's latest Sample Household Survey, satisfaction with noise levels slid to 74% from 75.7% in 2018, and noise was one of the two lowest-rated areas of HDB living. Neighbours and traffic were the main reasons, as reported by The Straits Times.

Heat makes it harder. Singapore bedrooms average 28.4°C at night, and in that study of 150 residents, about a third did not use aircon at all. Open windows let the city in.

What did the Penn sleep lab actually test?

Researchers led by Mathias Basner observed 25 healthy adults aged 21 to 41 over seven nights in a sleep lab, with eight hours in bed each night. None had used noise to help them sleep before, and none had a sleep disorder.

On different nights they slept with:

  1. No noise at all
  2. Recorded environmental noise, 93 events peaking at 45 to 65 dBA
  3. Pink noise at 40 or 50 dBA
  4. Environmental noise plus pink noise
  5. Environmental noise plus foam earplugs

Sleep was measured with polysomnography, the full lab recording of brain waves, so this was not a wearable estimate.

What did pink noise and earplugs do to sleep?

| Night condition (vs a quiet night) | What changed | |---|---| | Aircraft noise | About 23 fewer minutes of N3 deep sleep | | Pink noise alone at 50 dB | Nearly 19 fewer minutes of REM sleep | | Aircraft noise plus pink noise | Less deep sleep and less REM, plus about 15 more minutes awake | | Aircraft noise plus earplugs | Most of the deep sleep loss prevented |

Source: Penn Medicine, February 2026, and Basner et al., SLEEP 2026. Lab study of 25 healthy adults.

People felt it too. After noise nights or pink noise nights, participants said their sleep felt lighter, they woke more often and sleep quality was worse, unless they wore earplugs.

There were limits. Earplugs started to fail at the loudest level, 65 dBA. And morning cognition, heart measures and hearing tests did not change in this short study.

So does pink noise help at all?

A little, in one narrow way. A companion paper in Sleep Health found pink noise reduced noise-triggered awakenings and arousals in a dose-response pattern. That fits the idea of masking: a steady sound hides sudden ones.

But earplugs outperformed pink noise. The same paper ranked how likely each sound was to wake people. A crying baby and a fire alarm came top, followed by helicopter, low sonic boom, drone, rail, jet and road noise.

The authors were careful. They called for more research on noise colour, volume and long-term use, especially in children. Penn noted that young children spend much more time in REM sleep than adults, which is why the researchers urged caution with sound machines next to cots.

Why this matters now

Sleep sounds are huge. Penn's release says white noise and ambient podcasts account for three million daily hours on Spotify, and the top five "white noise" videos on YouTube have more than 700 million views. As many as 16% of Americans use earplugs to sleep.

That is a lot of nightly habit built on thin evidence. This is one lab study of 25 young adults, not the final word. But it is a rigorous one, and it questions an assumption most of us never test.

What can light sleepers try this week?

  1. Find your real noise source. Is it a neighbour, the road, a lift or the 3am rubbish truck? Steady noise and sudden spikes call for different fixes.
  2. Trial foam earplugs for 7 nights before buying a sound machine. Note how you feel each morning.
  3. If you use a sound app, keep it low and set a timer rather than playing it all night at volume. The study's REM drop was at 50 dB, roughly moderate rainfall.
  4. Remember fans and aircon make broadband sound too. Penn lists them alongside white noise. The study did not test them, so treat this as a reason to notice, not to worry.
  5. Cut the heat that forces windows open. A cooler bed lets you close the window on traffic. We covered why Singapore bedrooms run at 28.4°C, whether a fan helps in humid heat and how humidity links to REM and deep sleep.

Some hot sleepers pair a closed window with breathable bedding, like a cooling blanket or a cooling weighted blanket, instead of heavy quilts. If you are curious how a weighted blanket handles humid nights, the fabric and fill specs are listed in full.

If noise or poor sleep keeps dragging on for weeks, or you snore loudly or wake gasping, speak to a doctor. Earplugs and quiet are habits, not treatment.

So, what wakes you most at night: the neighbours, the road, or the aircon?

Sources

  • Basner M, et al. Efficacy of pink noise and earplugs for mitigating the effects of intermittent environmental noise exposure on sleep. SLEEP, 2026. https://academic.oup.com/sleep/article/49/5/zsag001/8452884 (PubMed: https://pubmed.ncbi.nlm.nih.gov/41627391/)
  • Penn Medicine News. Pink noise reduces REM sleep and may harm sleep quality. 2 February 2026. https://www.pennmedicine.org/news/pink-noise-reduces-rem-sleep-and-may-harm-sleep-quality
  • Basner M, et al. The efficacy of pink noise and earplugs for mitigating sleep disruption induced by different environmental noise sources. Sleep Health, 2026. https://pubmed.ncbi.nlm.nih.gov/42120238/ (doi: 10.1016/j.sleh.2026.03.009)
  • European Environment Agency. Environmental noise in Europe 2025. https://www.eea.europa.eu/en/analysis/publications/environmental-noise-in-europe-2025
  • World Health Organization. Environmental Noise Guidelines for the European Region, 2018 (recommendations table via NCBI Bookshelf). https://www.ncbi.nlm.nih.gov/books/NBK535301/table/ch8.tab11/
  • The Straits Times. Residents' satisfaction down in 13 out of 17 areas of HDB living, including cleanliness, noise, privacy. December 2025. https://www.straitstimes.com/singapore/housing/residents-satisfaction-down-in-13-out-of-17-areas-of-hdb-living-including-cleanliness-noise-privacy
  • The Straits Times. What's the temperature in the bedroom in S'pore? A muggy 28 deg C, says new study on residents. June 2026. https://www.straitstimes.com/singapore/environment/whats-the-temperature-in-the-bedroom-in-spore-a-muggy-28-deg-c-says-new-study-on-residents

This article is informational and not medical advice. Claims about sleep and wellbeing are general; for personal health concerns consult a qualified professional.