Clinical Answer: No evidence shows brown noise is better than white noise for sleep. No published trial compares them head to head, and brown noise has not been studied directly. Evidence for any continuous broadband noise as a sleep aid is very low quality, and newer PSG data suggest broadband noise may reduce REM sleep. If a pt sleeps in a noisy room, earplugs have better support than noise masking

Source of Recommendation: SOR C.
The answer rests on two systematic reviews of mostly small, heterogeneous, non-randomized studies of white and pink noise, plus one small randomized crossover PSG trial of pink noise. None tested brown noise. Any claim that brown beats white relies on extrapolation from other noise colors and on acoustic reasoning, which is disease-oriented rather than patient-oriented.

Evidence Used: Two systematic reviews and one randomized crossover trial address continuous noise and sleep, and none of them tested brown noise. Riedy and colleagues reviewed 38 studies of continuous white or broadband noise and found that study methods, noise exposures, and outcomes varied widely, with results ranging from improved sleep to disrupted sleep. Using GRADE, they rated the evidence for noise improving sleep as very low quality and cautioned that continuous noise may also harm sleep and hearing.

Capezuti and colleagues reviewed white noise, pink noise, and combined audio interventions in adults. Positive findings were reported in 6 white noise studies (33%), 9 pink noise studies (81.9%), and 4 multiaudio studies (66.7%). They concluded the evidence was not strong, though no study reported harm with short-term use. The higher positive rate for pink noise is the only signal that lower-frequency noise might outperform white noise. That is a vote count, not an effect size, so applying it to brown noise is indirect extrapolation.

Basner and colleagues ran a 7-night PSG study in 25 healthy adults with a mean age of 28.5 years, testing traffic-like noise, pink noise at 40 or 50 dBA, earplugs, and combinations. Compared with quiet nights, environmental noise reduced N3 and pink noise reduced REM, with a dose-dependent REM loss of about 19 minutes at 50 dBA. Earplugs blocked nearly all environmental noise effects until they began failing at 65 dBA. Morning cognition, cardiovascular measures, and hearing were unchanged, but subjective sleep, alertness, and mood were worse after noise exposure. The study was small, used young noise-naive adults in a lab, and tested only pink noise, so it may not apply to habitual users, pts with insomnia, children, or brown noise.

Taken together, the evidence shows no proven benefit of any noise color over another, a possible REM cost from broadband noise, and better support for earplugs than noise masking in noisy bedrooms.

References:

1. Riedy SM, Smith MG, Rocha S, Basner M. Noise as a sleep aid: a systematic review. Sleep Med Rev. 2021 Feb;55:101385. doi:10.1016/j.smrv.2020.101385. PMID: 33007706 (STEP 2)
2. Capezuti E, Pain K, Alamag E, et al. Systematic review: auditory stimulation and sleep. J Clin Sleep Med. 2022 Jun 1;18(6):1697-1709. doi:10.5664/jcsm.9860. PMID: 34964434 (STEP 2)
3. Basner M, Smith MG, Cordoza M, et al. Efficacy of pink noise and earplugs for mitigating the effects of intermittent environmental noise exposure on sleep. Sleep. 2026 May;49(5):zsag001. doi:10.1093/sleep/zsag001. PMID: 41627391 (STEP 2)