The Effect of White Noise on Newborns

Sleep Promotion

White noise is often used to support infant sleep. Constant background noise can mask sudden environmental sounds; as a result, babies are less likely to wake up unexpectedly (National Childbirth Trust [NCT], 2021). The theory is that the infant brain focuses on the steady hum rather than on disruptive stimuli, reducing sleep interruptions (NCT, 2021). Moreover, the noise resembles what babies hear in utero—continuous muffled sounds—providing a sense of security during falling asleep (Spencer, 2022).

Research suggests that white noise can indeed help newborns fall asleep faster and stay asleep longer. In a classic study of 40 infants, 80% fell asleep within five minutes with white noise, compared to only 25% in the control group (Spencer et al., 1990). Anecdotal evidence supports these findings: one childcare facility that introduced white noise in sleeping areas observed that babies slept on average two hours more per week than before (NCT, 2021). White noise also helped children continue sleeping even when disturbances, such as another baby crying, occurred nearby (NCT, 2021).

While these findings are promising, the overall evidence base remains limited. A systematic review of 38 studies concluded that results varied widely and rated the certainty of evidence as very low (Yoshida et al., 2021). In other words, many parents and clinicians report improvements with white noise, but large-scale research has yet to confirm this definitively (Yoshida et al., 2021). Some experts even warn that continuous background noise may disrupt normal sleep cycles if misused (Mindell, 2018). Therefore, careful and controlled use of white noise is advisable until further research provides clarity.

Soothing Effect

Besides sleep support, white noise is frequently used to calm crying or restless infants. The monotone sound mimics the womb environment, providing a soothing effect (Spencer, 2022). According to pediatricians of the American Academy of Pediatrics (AAP), white noise at low volume may calm babies because it resembles the muffled environment they experienced before birth (AAP, 2014).

Scientific studies confirm this calming effect. In a randomized study on colicky infants, the effect of white noise was compared to rocking. On days when babies were exposed to white noise, they cried significantly less and slept longer compared to days with rocking alone (Sahni et al., 2000). White noise proved more effective at reducing distress than physical soothing methods (Sahni et al., 2000).

The soothing effect is also measurable physiologically. In one study, exposure to white noise reduced heart rate and respiratory rate in young children, indicating a more relaxed state that supports sleep initiation (Mindell, 2018). In summary, white noise can serve as a valuable non-pharmacological tool to comfort newborns and reduce excessive crying, especially when mimicking familiar prenatal sounds.

General Development

Frequent or prolonged use of white noise raises questions about its impact on neurological and sensory development. Hearing is a primary concern. Some infant sleep machines produce sound levels exceeding 85 dB—comparable to heavy traffic or a lawnmower (AAP, 2014). Prolonged exposure at such levels can damage the sensitive hearing of infants (AAP, 2014).

The AAP therefore advises using infant sleep machines at a safe distance and low volume: ideally at least two meters from the crib and kept at or below 50 dB (AAP, 2014). Furthermore, it recommends limiting use to the falling-asleep phase, rather than playing noise continuously throughout the night (AAP, 2014).

Speech and language development is another consideration. Babies learn to speak by hearing and imitating voices and sounds around them. Continuous exposure to white noise could, in theory, reduce this exposure. Pediatricians emphasize that infants need to hear normal household sounds and parental voices regularly for healthy communication development (Cleveland Clinic, 2023).

Animal studies also raise caution. A recent review concluded that animals exposed to continuous white noise showed delayed auditory development and learning problems (Skeide et al., 2024). While such effects are harder to confirm in human infants, the findings suggest potential risks with prolonged exposure (Skeide et al., 2024).

Another issue is dependency. If babies always associate sleep with white noise, they may struggle to sleep without it later on. Experts therefore recommend gradually reducing white noise use as the infant grows—first limiting it to falling asleep, then phasing it out completely (Cleveland Clinic, 2023).

Conclusion

White noise can be a valuable tool in infant care when used wisely and moderately. For sleep, evidence suggests that soft background noise helps babies fall asleep faster and sleep more soundly (Spencer, 1990; NCT, 2021). As a soothing aid, white noise has shown measurable benefits in reducing crying (Sahni et al., 2000). However, it is not a cure-all, and caution is necessary. Volume should remain low, devices must be placed at a safe distance, and prolonged continuous use should be avoided to prevent hearing or developmental issues (AAP, 2014).

In summary, white noise provides short-term benefits for sleep and comfort, but safe, moderate use is crucial to avoid long-term risks (Skeide et al., 2024; Cleveland Clinic, 2023).

Disclaimer: This article is for informational purposes only and does not replace professional medical advice. Always consult your pediatrician or qualified healthcare provider with any questions or concerns about your baby’s health or sleep.