41% of US parents of children ages 0 to 13 say a sound machine is part of their child’s bedtime routine, nearly as common as reading a book before bed (46%) (National Sleep Foundation, Sleep in America Poll 2026). Adults are doing the same: 39% of British adults play music, podcasts or other sounds to get to sleep at least some nights (YouGov, 2025), and the top five white noise videos on YouTube have been watched more than 700 million times (Basner et al., Sleep, 2026). The science has not kept pace with the habit. A 38-study systematic review rated the evidence that continuous noise improves sleep as very low (Sleep Medicine Reviews, 2021), and a 2026 polysomnography trial found pink noise cut REM sleep by up to 29 minutes a night. For the wider picture on how much and how well people sleep, see our sleep statistics. We aggregated data from the National Sleep Foundation, the CDC and NCHS, the European Environment Agency, the World Health Organization, YouGov, peer-reviewed trials and meta-analyses in Sleep, Sleep Medicine, Sleep Medicine Reviews, Pediatrics and Cureus, NIOSH, NIDCD and the Cochrane Library.
TL;DR
- 41% of US parents use a sound machine in their child’s bedtime routine (National Sleep Foundation, Sleep in America Poll 2026).
- 39% of GB adults play sounds to get to sleep at least some nights; 10% every night (YouGov, January 2025).
- 59.3% of 253 parents at a US pediatric clinic used white noise for their child, for a mean 9.6 hours a day (Gawel et al., Cureus, 2026).
- The top 5 white noise videos on YouTube have more than 700 million views (Basner et al., Sleep, 2026).
- Calm reports more than 180 million downloads (Calm, About page, 2026).
- Evidence that continuous noise improves sleep was rated very low quality across 38 studies (Riedy et al., Sleep Medicine Reviews, 2021).
- White noise lowered PSQI scores by 3.70 points in adults across 12 RCTs (Ding et al., Sleep Medicine, 2025).
- Pink noise at 50 dBA reduced REM sleep by 18.6 minutes versus a quiet night (Basner et al., Sleep, 2026).
- All 14 infant sleep machines tested exceeded 50 dBA at 30 cm, and 3 exceeded 85 dBA (Hugh et al., Pediatrics, 2014).
- Over 20% of Europeans are exposed to harmful transport noise; 4.6 million suffer severe sleep disturbance (EEA, Environmental Noise in Europe 2025).
- 14.5% of US adults had trouble falling asleep most days or every day (NCHS Data Brief 436, 2020 data).
- Sound therapy showed no evidence of superiority over placebo or education for tinnitus across 8 studies (Cochrane, 2018).
1. The Demand Side: Short Sleep and Noisy Bedrooms
Sound conditioners sell into two problems at once: people who struggle to fall or stay asleep, and bedrooms that are louder than health guidance allows. Between 30% (Vermont) and 46% (Hawaii) of adults in every US state slept less than the recommended 7 hours in 2022 (CDC, Sleep in Adults FastStats), and the CDC notes the share not getting enough sleep stayed the same from 2013 to 2022. A decade of flat numbers is the market opportunity in one line: nothing mainstream has moved the needle.
The noise half of the equation is better measured in Europe. The European Environment Agency counts more than one in five Europeans exposed to harmful transport noise, over 30% against WHO thresholds, and about 4.6 million with severe sleep disturbance (EEA, Environmental Noise in Europe 2025). The WHO night limits are strict: below 45 dB Lnight for road traffic, 44 dB for rail and 40 dB for aircraft (WHO Europe, Environmental Noise Guidelines). Masking sound is the cheapest thing a household can buy against noise it cannot control. Our noise pollution statistics cover the exposure data in depth.
| Metric | Value | Source |
|---|---|---|
| Adults with short sleep, lowest vs highest state, 2022 | Vermont 30% vs Hawaii 46% | CDC, BRFSS via Sleep in Adults FastStats |
| Short sleep among men / adults 45-64 / NHPI adults, 2022 | 37% / 39% / 49% | CDC, BRFSS via Sleep in Adults FastStats |
| Adults with trouble falling asleep most days or every day, 2020 | 14.5% (women 17.1%, men 11.7%) | NCHS Data Brief 436 (2022) |
| Adults with trouble staying asleep most days or every day, 2020 | 17.8% (nonmetro 22.4% vs large central metro 14.4%) | NCHS Data Brief 436 (2022) |
| Children 4 months to 5 years with insufficient sleep, 2020-2021 | 37% | CDC, National Survey of Children’s Health via FastStats |
| Children not consistently getting NSF-recommended sleep | 44% | National Sleep Foundation, Sleep in America Poll 2026 |
| Europeans exposed to harmful transport noise | Over 20% (over 30% vs WHO levels); 4.6 million with severe sleep disturbance | EEA, Environmental Noise in Europe 2025 |
| WHO night noise limits (Lnight) | Road 45 dB, rail 44 dB, aircraft 40 dB | WHO Europe, Environmental Noise Guidelines (2018) |
Context note: income matters as much as geography. Trouble falling asleep reached 21.9% among adults below the federal poverty level versus 12.6% at 200% or more of it (NCHS Data Brief 436). Most recent available national data on sleep difficulty: NCHS, 2020.
2. Adoption: Who Actually Turns the Machine On
The sound machine has become standard nursery equipment rather than a niche gadget. In the National Sleep Foundation’s 2026 poll of 977 caregivers, 41% named a sound machine as part of their child’s bedtime routine, behind blackout curtains (49%) and reading a book (46%) and well ahead of singing a song (26%) (NSF, Sleep in America Poll 2026). Parents of infants under one year were more likely still to use one. The habit sits alongside, not instead of, screen hygiene: 69% of parents said their child avoids devices in the hour before bed.
Clinic data put the number higher. At a pediatric otolaryngology clinic in Buffalo, 59.3% of 253 parents of children aged eight or younger used white noise (Gawel et al., Cureus, 2026). Adults are not far behind: 39% of British adults play some sound to fall asleep at least some nights, and one in ten does it every single night (YouGov, January 2025). The behavior is mainstream enough that the question is no longer whether people use sleep sound, but how loud and for how long.
| Metric | Value | Source |
|---|---|---|
| Parents using a sound machine in child’s bedtime routine (ages 0-13) | 41% | National Sleep Foundation, Sleep in America Poll 2026 |
| Other bedtime routine components | Blackout curtains 49%, reading 46%, nightlight 37%, music or stories on a device 18% | National Sleep Foundation, Sleep in America Poll 2026 |
| Families using sleep-monitoring technology at bedtime | 22% | National Sleep Foundation, Sleep in America Poll 2026 |
| Parents at a US pediatric clinic using white noise for their child | 59.3% (150 of 253) | Gawel et al., Cureus (2026) |
| Users relying on a bedroom white noise machine vs a mobile app | 82.0% vs 7.3% | Gawel et al., Cureus (2026) |
| GB adults who play sounds to get to sleep | 39% (some nights 20%, most nights 9%, every night 10%) | YouGov Daily Question, January 16, 2025 (n=6,072) |
| GB adults who never do | 57% | YouGov Daily Question, January 16, 2025 |
Context note: the NSF poll was fielded September 12 to October 5, 2025 on the Ipsos KnowledgePanel; the Cureus sample is a single specialty clinic and likely overstates national use. Hardware still dominates in nurseries: dedicated machines outnumber phone apps by more than ten to one in the Buffalo sample.
3. Streaming and Apps: Sleep Sound Goes Digital
Outside the nursery, the sound conditioner is increasingly a playlist. The top five results for ‘white noise’ on Apple’s App Store carry more than 1 million reviews, and the top five YouTube videos for the same query have more than 700 million views, according to searches run on July 15, 2025 by the authors of a 2026 pink noise trial (Basner et al., Sleep, 2026). The same paper cites a 2023 Bloomberg document putting white noise and ambient podcasts at 3 million daily consumption hours on Spotify.
Meditation and sleep apps sit on top of that funnel. Calm now reports more than 180 million downloads and 3 million five-star reviews (Calm, About), up from the 150 million it reported in 2024 as cited in a November 2025 perspective in Sleep (Vazzaz et al., Sleep, 2025). That paper also counted 9 sleepcasts among the top 50 health and fitness podcasts on Spotify UK. The commercial point: free streams compete directly with the physical machine, and the attention economy now funds a lot of nighttime audio. The podcast side is broken down in our sleep podcast statistics.
| Metric | Value | Source |
|---|---|---|
| Reviews on top 5 ‘white noise’ apps, Apple App Store | More than 1 million | Basner et al., Sleep (2026), searches of July 15, 2025 |
| Views of top 5 ‘white noise’ videos on YouTube | More than 700 million | Basner et al., Sleep (2026) |
| Reviews on top 5 Amazon bestsellers in ‘white noise machines’ | More than 100,000 | Basner et al., Sleep (2026) |
| White noise and ambient podcast listening on Spotify | 3 million daily consumption hours | Bloomberg (2023), cited in Basner et al., Sleep (2026) |
| Followers of Spotify’s most popular sleep playlist | Over 6 million | Spotify Community (2024), cited in Vazzaz et al., Sleep (2025) |
| Sleepcasts among top 50 health and fitness podcasts, Spotify UK | 9 | Spotify Podcast Charts (2024), cited in Vazzaz et al., Sleep (2025) |
| Calm app downloads | Over 180 million (150 million in 2024) | Calm, About page (2026); Vazzaz et al., Sleep (2025) |
Context note: review and view counts are popularity proxies, not user counts, and the Spotify figures are second-hand. We found no independently verifiable market-size figure for white noise machines, so none is included (see Data watch).
4. The Evidence For: What Trials Say Sound Masking Does
The supportive evidence is real but narrow. A December 2025 meta-analysis of 12 randomized trials and 1,301 participants found white noise lowered Pittsburgh Sleep Quality Index scores by 3.70 points in adults (95% CI -4.90 to -2.50) and 2.71 points in older adults (Ding et al., Sleep Medicine, 2025). A May 2026 randomized trial in 60 adults aged 65 and over in Iran found PSQI scores falling from 11.5 to 9.2 after 30 nights of white noise plus sleep hygiene, with no change in controls (Mousavi et al., BMC Geriatrics, 2026).
The widely quoted ‘38% faster’ figure comes from one small lab study: broadband sound cut sleep onset latency to stage 2 sleep by about 38% in 18 healthy subjects whose bedtime was delayed 90 minutes to simulate transient insomnia (Messineo et al., Frontiers in Neurology, 2017). The broader verdict is less flattering. Riedy, Smith, Rocha and Basner screened three databases, included 38 articles and, under GRADE criteria, rated the quality of evidence that continuous noise improves sleep as very low, ‘which contradicts its widespread use’ (Riedy et al., Sleep Medicine Reviews, 2021).
| Metric | Value | Source |
|---|---|---|
| Studies in the most comprehensive systematic review of continuous noise and sleep | 38 articles; evidence quality rated very low (GRADE) | Riedy et al., Sleep Medicine Reviews (2021) |
| RCTs and participants in 2025 meta-analysis | 12 RCTs, 1,301 participants (356 infants/toddlers, 648 adults, 297 older adults) | Ding et al., Sleep Medicine (2025) |
| PSQI change with white noise, adults | -3.70 points (95% CI -4.90 to -2.50) | Ding et al., Sleep Medicine (2025) |
| PSQI change with white noise, older adults | -2.71 points (95% CI -4.98 to -0.44) | Ding et al., Sleep Medicine (2025) |
| Sleep onset latency to stage 2, broadband sound vs normal noise | About 38% shorter (n=18) | Messineo et al., Frontiers in Neurology (2017) |
| PSQI in older adults after 30 nights of white noise | 11.5 to 9.2 (n=60) | Mousavi et al., BMC Geriatrics (2026) |
Context note: most trials measure subjective sleep quality (PSQI), not polysomnography, and the Sleep perspective by Vazzaz and colleagues concluded that music-based relaxation has demonstrated efficacy, whereas findings on ambient sounds such as white or pink noise are inconclusive. Messineo (2017) is most recent available data for that outcome.
5. The Evidence Against: Pink Noise and Lost REM Sleep
2026 produced the most rigorous test yet of the products people actually use, and it complicates the marketing. Pink noise played at 50 dBA reduced REM sleep by 18.6 minutes compared with a noise-free night, and by 29.0 minutes when layered on top of traffic and aircraft noise, in a seven-night polysomnography study of 25 healthy adults led by Mathias Basner (Basner et al., Sleep, 2026). Adding pink noise to environmental noise worsened overall sleep structure despite minor improvements in fragmentation, and participants rated sleep, alertness and mood worse after pink noise nights.
Foam earplugs did better. They mitigated nearly all environmental noise effects, with no significant difference in sleep structure from a quiet night, until noise peaked at 65 dBA, and the authors concluded that the REM findings ‘caution against the widespread and indiscriminate use of broadband noise’. A companion paper by the same team, also in 25 adults exposed to 93 noise events, found pink noise reduced aircraft-noise arousals in a dose-response manner but was outperformed by earplugs (Basner et al., Sleep Health, 2026). A smaller crossover study pointed the other way on one outcome: 45 dB pink noise reduced the impact of traffic noise on sleep and on the blood metabolome in 12 people (Vincens et al., Communications Medicine, 2026). Masking is a trade, not a free lunch.
| Metric | Value | Source |
|---|---|---|
| Study design | 25 healthy adults, 7 nights, 93 noise events at 45-65 dBA, pink noise at 40 or 50 dBA | Basner et al., Sleep (2026) |
| REM change, pink noise 50 dBA alone vs quiet night | -18.6 minutes | Basner et al., Sleep (2026) |
| REM change, environmental noise plus pink noise 40 / 50 dBA vs quiet night | -21.5 / -29.0 minutes | Basner et al., Sleep (2026) |
| N3 deep sleep change, environmental noise alone vs quiet night | -23.4 minutes | Basner et al., Sleep (2026) |
| N3 recovered vs environmental noise: pink noise 50 dBA vs earplugs | +7.7 vs +16.9 minutes | Basner et al., Sleep (2026) |
| Wake time, environmental noise plus pink noise 50 dBA vs quiet night | +15.4 minutes | Basner et al., Sleep (2026) |
| Pink noise vs earplugs on aircraft-noise arousals | Pink noise reduced arousals dose-dependently but was outperformed by earplugs | Basner et al., Sleep Health (2026) |
| Pink noise 45 dB and traffic noise, crossover pilot | Reduced impact on sleep and blood metabolome (n=12) | Vincens et al., Communications Medicine (2026) |
Context note: participants were young (mean age 28.5) and only seven were male, and morning cognition, cardiovascular measures and hearing were not affected. The study was registered as NCT05774977.
6. Infants and Children: Volume, Hours and Who Gives the Advice
The nursery is where volume and duration collide. All 14 infant sleep machines tested at maximum volume exceeded 50 dBA at 30 cm, the recommended noise limit for hospital nurseries, and 3 of them topped 85 dBA (Hugh et al., Pediatrics, 2014). The authors noted that 85 dBA for more than 8 hours exceeds adult occupational limits; NIOSH sets its recommended exposure limit at 85 dBA averaged over an eight-hour workday (NIOSH, About Noise and Hearing Loss).
Real-world exposure is long. In the 2026 Buffalo clinic survey, 90.7% of families who used white noise played it overnight, for a mean of 9.6 hours a day, and white noise users had younger children (mean age 3.3 versus 4.4 years) (Gawel et al., Cureus, 2026). Advice flows mostly peer to peer: 58.0% heard about it from friends or family and 18.0% from social media, against 16.0% from a healthcare provider. The study did not measure volume or placement, which is exactly the gap Hugh and colleagues flagged a decade earlier. Hearing risk from everyday listening is tracked in our hearing loss from headphones statistics.
| Metric | Value | Source |
|---|---|---|
| Infant sleep machines exceeding 50 dBA at 30 cm, maximum volume | 14 of 14 | Hugh et al., Pediatrics (2014) |
| Machines exceeding 85 dBA | 3 of 14 | Hugh et al., Pediatrics (2014) |
| NIOSH recommended exposure limit | 85 dBA averaged over 8 hours | NIOSH, CDC |
| White noise played overnight (users) | 90.7% | Gawel et al., Cureus (2026) |
| Mean daily white noise exposure | 9.6 hours (SD 2.6) | Gawel et al., Cureus (2026) |
| Where parents learned about white noise | Friends/family 58.0%, social media 18.0%, provider 16.0%, search engine 10.0% | Gawel et al., Cureus (2026) |
| Parents’ main motivations | Improve sleep quality 64.7%, cover environmental noise 61.3%, faster sleep onset 48.0% | Gawel et al., Cureus (2026) |
| 24-hour total sleep time with white noise, infants and toddlers | +137.51 minutes (95% CI 67.80 to 207.23); nocturnal 12-hour effect not significant | Ding et al., Sleep Medicine (2025) |
Context note: Hugh et al. (2014) is the most recent available data on measured infant machine output; products have changed since, but no newer independent test was found. White noise use was not associated with parental concerns about speech or hearing development in the Cureus survey, which measured perceptions, not hearing outcomes.
7. Clinical Uses: Hospital Wards and Tinnitus
Hospitals are the one setting where the trial evidence leans consistently positive. A 2025 systematic review of 7 randomized trials and 496 hospitalized adults concluded that white noise and similar masking noise ‘seem to improve sleep efficiency’, with only 8 participants dropping out for discomfort (Khandelwal et al., Sleep Medicine: X, 2025). Four of the seven trials ran in intensive care units, and white noise was typically delivered at 40 to 50 dB. The 2025 Sleep Medicine meta-analysis found a larger PSQI effect in ICU patients (-4.04) than outside the ICU (-2.61).
Tinnitus is the other big clinical use, and the evidence is weaker than its popularity suggests. NIDCD says 10 to 25% of adults have tinnitus and lists tabletop, smartphone and wearable sound generators among management options (NIDCD, Tinnitus). Yet a 2018 Cochrane review of 8 studies and 590 participants found no evidence that sound therapy beats a waiting list, placebo or education, with low-certainty evidence (Sereda et al., Cochrane Database of Systematic Reviews, 2018). See our tinnitus statistics for prevalence detail.
| Metric | Value | Source |
|---|---|---|
| RCTs and hospitalized adults reviewed | 7 RCTs, 496 participants (43.9% women) | Khandelwal et al., Sleep Medicine: X (2025) |
| Trials run in ICUs | 4 of 7 | Khandelwal et al., Sleep Medicine: X (2025) |
| Participants who discontinued due to discomfort | 8 | Khandelwal et al., Sleep Medicine: X (2025) |
| PSQI change with white noise, ICU vs non-ICU | -4.04 vs -2.61 points | Ding et al., Sleep Medicine (2025) |
| US adults with tinnitus | 10 to 25% | NIDCD, Tinnitus |
| Sound therapy for tinnitus vs waiting list, placebo or education | No evidence of superiority; 8 studies, 590 participants, low certainty | Sereda et al., Cochrane (2018) |
| Sound masking for tinnitus, earlier review | 6 RCTs, 553 participants; no significant change in loudness or severity | Hobson et al., Cochrane (2012) |
Context note: the Cochrane authors stress that absence of conclusive evidence is not evidence of no effect (Hobson et al., Cochrane, 2012), and no adverse effects were reported from sound-creating devices. Both Cochrane reviews are most recent available data for this question.
Summary: White Noise Machine & Sleep Sound by the Numbers
| Metric | Value | Source |
|---|---|---|
| US parents using a sound machine at bedtime (kids 0-13) | 41% | NSF, Sleep in America Poll 2026 |
| Parents at a US pediatric clinic using white noise | 59.3% | Gawel et al., Cureus (2026) |
| GB adults who play sounds to get to sleep | 39% (10% every night) | YouGov, January 2025 |
| Views of top 5 ‘white noise’ YouTube videos | More than 700 million | Basner et al., Sleep (2026) |
| White noise and ambient podcasts on Spotify | 3 million daily hours | Bloomberg (2023) via Basner et al. (2026) |
| Calm downloads | Over 180 million | Calm (2026) |
| Short sleep among adults, state range, 2022 | 30% to 46% | CDC, BRFSS |
| Adults with trouble falling asleep most days | 14.5% | NCHS Data Brief 436 |
| Europeans with severe noise-related sleep disturbance | About 4.6 million | EEA (2025) |
| WHO road traffic night noise limit | 45 dB Lnight | WHO Europe |
| Evidence quality, continuous noise and sleep | Very low (38 articles) | Riedy et al., Sleep Medicine Reviews (2021) |
| PSQI improvement with white noise, adults | -3.70 points | Ding et al., Sleep Medicine (2025) |
| Sleep onset latency with broadband sound | About 38% shorter (n=18) | Messineo et al. (2017) |
| REM lost with pink noise 50 dBA | 18.6 minutes | Basner et al., Sleep (2026) |
| REM lost with noise plus pink noise 50 dBA | 29.0 minutes | Basner et al., Sleep (2026) |
| Infant machines over 50 dBA at 30 cm | 14 of 14 | Hugh et al., Pediatrics (2014) |
| Infant machines over 85 dBA | 3 of 14 | Hugh et al., Pediatrics (2014) |
| Mean daily white noise exposure, children | 9.6 hours | Gawel et al., Cureus (2026) |
| Hospital trials of sound machines reviewed | 7 RCTs, 496 adults | Khandelwal et al. (2025) |
| Sound therapy for tinnitus vs placebo | No evidence of superiority | Cochrane (2018) |
Methodology and Sources
Every figure above was read during research for this article in a government page, a peer-reviewed paper or abstract (via the Europe PMC API) or the publisher’s own page. Statistics circulating on retail and SEO blogs without a primary document, including several widely repeated adoption and market-size percentages, were excluded.
- National Sleep Foundation: Sleep in America Poll 2026, Sleep Health of American Youth and Sleep in America Polls index
- CDC: Sleep in Adults FastStats (BRFSS 2022), Sleep in Children FastStats (NSCH 2020-2021), NCHS Data Brief 436, Sleep Difficulties in Adults: United States, 2020, NIOSH, About Noise and Hearing Loss
- European Environment Agency: Environmental Noise in Europe 2025
- WHO Regional Office for Europe: Environmental Noise Guidelines for the European Region
- YouGov: Daily Question, how often do you play sounds to get to sleep, January 16, 2025
- Calm: About Calm
- Basner M et al.: Efficacy of pink noise and earplugs for mitigating the effects of intermittent environmental noise exposure on sleep, Sleep, 2026; The efficacy of pink noise and earplugs for mitigating sleep disruption induced by different environmental noise sources, Sleep Health, 2026
- Vincens N et al.: Pink noise reduces impact of traffic noise on sleep and the blood metabolome, Communications Medicine, 2026
- Vazzaz J et al.: Between sound and sleep: a perspective on Sonic Sleep Aids, Sleep, 2025
- Riedy SM et al.: Noise as a sleep aid: A systematic review, Sleep Medicine Reviews, 2021
- Ding Y et al.: Impact of white noise on sleep quality across age groups and in critically ill/non-critically ill patients, Sleep Medicine, 2025
- Messineo L et al.: Broadband Sound Administration Improves Sleep Onset Latency in Healthy Subjects in a Model of Transient Insomnia, Frontiers in Neurology, 2017
- Mousavi SAV et al.: The effect of white noise on sleep quality and fatigue in community-dwelling older adults, BMC Geriatrics, 2026
- Hugh SC, Wolter NE, Propst EJ, Gordon KA, Cushing SL, Papsin BC: maximum output levels of 14 infant sleep machines, Pediatrics, 2014
- Gawel EM et al.: Patterns and Motivations for White Noise Use in Children, Cureus, 2026
- Khandelwal K et al.: Impact and efficacy of sound machine on sleep in hospitalized adults: A systematic review, Sleep Medicine: X, 2025
- NIDCD: Tinnitus
- Cochrane Library: Sereda M et al., Sound therapy (using amplification devices and/or sound generators) for tinnitus, 2018; Hobson J et al., Sound therapy (masking) in the management of tinnitus in adults, 2012
- Data watch: No white noise machine market-size figure is included because the commercial research pages we tried (Grand View Research and others) were blocked or returned unrelated reports, so no two firms could be cross-checked. The Spotify figures (3 million daily hours, 6 million playlist followers, 9 sleepcasts) are second-hand: they come from a 2023 Bloomberg document and 2024 Spotify pages as cited in peer-reviewed papers, and the primary pages could not be read. Calm’s download count rose from 150 million (2024, per Vazzaz et al.) to over 180 million on its current About page; it is a company-reported figure. App Store, YouTube and Amazon counts are snapshots from July 15, 2025 searches. The NSF 41% is a bedtime-routine component reported by caregivers, not a household ownership rate; the Cureus 59.3% comes from one specialty clinic. The CDC adult page does not publish a single national short-sleep percentage for 2022, only subgroup and state figures. Older baselines kept for context: Hugh et al. (2014), Messineo et al. (2017), Riedy et al. (2021), Cochrane (2012, 2018) and NCHS sleep difficulty (2020 data). The WHO guideline landing page is dated 2019, while the guidelines carry a 2018 release. The Basner trial enrolled 25 young adults, so its REM results may not generalize to older sleepers or infants.
Last updated: October 3, 2026. We update this roundup quarterly, and the next refresh is expected when the National Sleep Foundation publishes its 2027 Sleep in America Poll and the CDC releases its next BRFSS sleep duration estimates.