Continuous white noise exposure during sleep and childhood development: A scoping review.

Background: White noise machines are widely used as a sleep aid for young children and may lead to poor hearing, speech, and learning outcomes if used incorrectly.

Objective: Characterize the potential impact of chronic white noise exposure on early childhood development.

Methods: Embase, Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, Scopus, and Web of Science were searched from inception through June 2022 for publications addressing the effects of chronic noise exposure during sleep on early development in animals and children. PRISMA-ScR guidelines were followed. Among 644 retrieved publications, 20 met inclusion criteria after review by multiple authors. Seven studies evaluated animal models and 13 studies examined pediatric subjects, including 83 animal and 9428 human subjects.

Results: White noise machines can exceed 91 dB on maximum volume, which exceeds the National Institute for Occupational Safety and Health noise exposure guidelines for a 2-h work shift in adults. Evidence suggests deleterious effects of continuous moderate-intensity white noise exposure on early development in animal models. Human subject data generally corroborates these models; however, studies also suggest low-intensity noise exposure may be beneficial during sleep.

Conclusions: Existing data support the limitation of maximal sound intensity and duration on commercially available white noise devices. Further research into the optimal intensity and duration of white noise exposure in children is needed.