Table 2.
A study on sleep induction using pure colored noise as an auditory stimulus.
| First Author, Year, Country | Study Design | Participants | N, Mean Age ± SD (or Range) |
Noise (Method) |
Intervention Duration | Control Group | Sleep Measure(s) | Sleep Outcomes |
|---|---|---|---|---|---|---|---|---|
| Spencer (1990) England | Randomized controlled trial | Healthy neonates | 40, (2–7 days old) | White noise (speaker) | Four and a half minutes | Not exposed to white noise | Observed by a single investigator | 80% of babies fell asleep when they were exposed to the white noise compared with 25% who fell asleep in the control group. |
| Forquer&Johnson (2007) USA |
Crossover | Healthy college students | 4, 19 | White noise (speaker) | Continuously from bedtime to waking for 7 nights | None | Sleep diary, PSQI, sleep hygiene test | Decrease in both sleep latency and night wakings during treatment |
| Rosalez (2020) | Crossover | ADHD Children | 3 (9–11) | White noise (speaker) |
Continuous at night | Not exposed to white noise | Sleep diary | Decreased bedtime sleep latency and spontaneous night wakings at home |
| Ebben (2021) USA |
Crossover | Adults with insomnia | 10, 58 (39–74) | White noise (speaker) |
2nd week of 3 weeks, | None | Daily sleep diary and actigraphy | Reduced WASO and sleep latency, reduced the number of awakenings during the night, improved sleep efficiency |
| Cho (2021) Korea |
Randomized controlled trial | Adult inpatient | 61 | White noise (earphone) |
1 h per night for 3 days | Wear earplugs | VSH, actigraphy | Positive effects on subjective sleep quality, improved sleep time and sleep efficiency |
| Messineo (2017) USA |
Crossover | Healthy adults | 18 (20–65) | Broadband (speaker) |
1 of 2 weeks | None | PSG, PSQI, VAS, SSS | Reduced sleep onset latency, improved subjective sleep quality |
| Kawada (1993) Japan |
Crossover | Healthy young subjects | 4, 19.8 (19–21) | Pink noise (speaker) |
1 of 2 days | None | PSG | Reduced sleep latency |
| Garcia-Molina (2020) USA |
Crossover | Healthy subjects | 7, 33.6 ± 8.7 | Pink noise (headband) |
4 of 5 sleep sessions | None | PSG | Reduced slap latency |