Claim reviewed: Steady broadband noise (white, pink, brown) makes other ambient sounds less noticeable.
What do we know?
Auditory masking is an established psychoacoustic phenomenon: a steady sound raises the detection threshold of other sounds in similar frequency bands. This is why noise is used to cover ambient sounds.
What don't we know?
It is not clear that masking translates into protected sleep: in a 25-person lab study, adding pink noise to intermittent environmental noise worsened sleep structure further, and earplugs worked better. A systematic review warns that continuous noise may also affect hearing.
Wording we use in the app: Helps mask surrounding sounds.
Sources (3)
Moore 2013 · Textbook
A standard textbook of auditory perception. Its chapter on frequency selectivity and masking describes how one sound raises the detection threshold of another (auditory masking) and how this depends on frequency bands.
6th edition.
Moore BCJ. An Introduction to the Psychology of Hearing. Brill; 2013. ISBN 9789004252424 Go to source
Basner ve ark. 2026 · Randomised controlled trial · 25 participants
A seven-night laboratory study in 25 healthy adults: intermittent environmental noise mainly reduced deep sleep (N3), whereas pink noise mainly reduced REM sleep, and adding pink noise to environmental noise worsened sleep structure further. Earplugs prevented most environmental-noise effects. The authors caution against widespread, indiscriminate use of broadband noise.
Pink noise alone (50 dBA) vs a quiet night: REM sleep −18.6 min (p = .0003)
Basner M, Smith MG, Cordoza M, Kayser MS, Carlin M, Ecker AJ, et al. Efficacy of pink noise and earplugs for mitigating the effects of intermittent environmental noise exposure on sleep. Sleep. 2026;49(5):zsag001. doi:10.1093/sleep/zsag001 PMID 41627391 Go to source
Riedy ve ark. 2021 · Systematic review · 38 studies
Across 38 studies of continuous white or similar broadband noise and sleep, findings ranged from noise helping sleep to disrupting it. By GRADE, the quality of evidence that continuous noise benefits sleep was very low; the authors warn that continuous noise may also harm sleep and hearing.
Riedy SM, Smith MG, Rocha S, Basner M. Noise as a sleep aid: A systematic review. Sleep Med Rev. 2021;55:101385. doi:10.1016/j.smrv.2020.101385 PMID 33007706 Go to source
Last reviewed: 3 October 2026 · Next review: 3 April 2027