Department of Otolaryngology - Head and Neck Surgery, St. Louis University Hospital, 1008 S Spring Ave, St. Louis, Missouri, 63104, USA.
Saint Louis University School of Medicine, 1402 S Grand Blvd, St. Louis, Missouri, 63104, USA.
Int J Pediatr Otorhinolaryngol. 2021 Jul;146:110757. doi: 10.1016/j.ijporl.2021.110757. Epub 2021 May 11.
To measure the sound intensity of popular infant white noise machines and Apple iPhone applications (apps) as they vary with volume setting and distance, and compare these output levels with current National Institute for Occupational Safety and Health (NIOSH) noise exposure threshold recommendations.
A total of eight infant white noise machines and six iPhone applications were included in the study based on product rating, number of ratings, and cost. The NIOSH Sound Level Meter application through the Apple App Store was used to measure output levels in A-weighted decibels (dBA). Each device was tested at its lowest and highest volume setting and at speaker-to-microphone distances simulating placement within a crib (10 cm), just outside of a crib rail (30 cm), and on a nightstand across the room (100 cm).
At the minimum volume setting, no device exceeded the NIOSH recommended noise exposure threshold of 85 dBA at any distance tested. At maximum volume setting, nine out of fourteen (64.3%) devices exceeded output levels of 85 dBA at a speaker-to-microphone distance of 10 cm. No device exceeded the recommended threshold at its maximal volume when placed 30 cm or 100 cm away.
Excessive white noise exposure has the potential to lead to noise-induced hearing loss and other adverse health effects in the neonatal and infant population. We recommend conservative use of white noise machines and apps by avoiding maximal volume setting and placing any device well outside of the crib or at least 30 cm away from the child. To promote safe use of white noise devices, future studies are needed to fully understand the association between early noise exposure and hearing loss in infants.
测量流行婴儿白噪声机器和苹果 iPhone 应用程序（apps）的声强，因为它们随音量设置和距离而变化，并将这些输出水平与当前国家职业安全与健康研究所（NIOSH）的噪声暴露阈值建议进行比较。
根据产品评分、评分数量和成本，共有 8 台婴儿白噪声机器和 6 个 iPhone 应用程序被纳入研究。使用苹果应用商店中的 NIOSH 声级计应用程序以 A 加权分贝（dBA）测量输出水平。每个设备都在最低和最高音量设置以及模拟放置在婴儿床内（10cm）、婴儿床栏杆外（30cm）和床头柜上（100cm）的扬声器到麦克风距离下进行测试。
在最小音量设置下，没有设备在任何测试距离超过 NIOSH 推荐的噪声暴露阈值 85dBA。在最大音量设置下，14 台设备中有 9 台（64.3%）在扬声器到麦克风距离为 10cm 时超过 85dBA 的输出水平。当放置在 30cm 或 100cm 远时，没有设备在最大音量下超过推荐阈值。
过度的白噪声暴露有可能导致新生儿和婴儿群体的噪声性听力损失和其他不良健康影响。我们建议谨慎使用白噪声机器和应用程序，避免最大音量设置，并将任何设备远离婴儿床或至少放在 30cm 远的地方。为了促进白噪声设备的安全使用，需要进行未来的研究，以充分了解婴儿早期噪声暴露与听力损失之间的关系。
