Are Sound Machines Bad for Babies? What New Research Suggests About Sleep, Hearing, and Brain Development

Baby Sleep

Jun 21

New research suggests that constant nighttime noise—even pink noise, often considered gentler than white noise—may reduce REM sleep. Combined with existing concerns about hearing safety and auditory development, these findings raise an important question: Should sound machines be a routine part of every baby's sleep environment?

We’ve been exploring this topic more in the last few years, steering parents away from too loud and monotonous sounds – with guidelines for parents on volume and type of sounds for nurseries and little kids’ rooms. We’ve also explored the benefits to phasing sound machines out, after around 3 months of age.

Now, a recent study gives us even more pause. We’re seeing evidence starting to mount that less input (sound) at night is better for the brain and for sleep quality and that constant noise in our babies’ sleep environment should not be a given.

Should I Use a Sound Machine in My Baby's Room?

Our short answer: probably less than most families currently do. While sound machines may help soothe newborns and mask disruptive noises in some homes, continuous nighttime noise may have downsides for REM sleep, hearing health, and auditory development. We increasingly encourage parents to use the lowest volume possible, for the shortest period needed, and to feel confident that many babies sleep well without a sound machine at all.

💡Learn how to survive the 4 month sleep regression in our Babies 3-5 months class.

The Recent Study on Pink Noise and Sleep

A 2026 study from UPenn found that pink noise (similar to white noise, but a deeper sound) significantly reduced the time spent in REM. REM is dream sleep, which is vital for emotional processing, memory and more. The study participants were adults, but for now, that’s the research population we have to extrapolate from. The subjects were monitored in a sleep lab as they were exposed to either intermittent environmental noise (a fire truck, an airplane noise), pink noise, both, or a quiet room.

While pink noise (played at 50 decibels, an average volume for a sound machine) reduced the time spent in REM sleep, environmental noises reduced the time spent in deep sleep. The best sleep overall happened in a quiet room.

This brings up an important point: why are we using sound machines in our babies’ bedrooms in the first place? Should we be skeptical about the marketing push for these products?

Does White Noise Soothe Newborn Babies?

One of the reasons we put noise in the room is because we think it mimics the sounds babies hear in utero. This could be true for newborns (which is also why people shush them), and it does seem to settle very young babies' nervous systems. But the effect fades after a month or two, and babies, like the rest of us, sleep well in a quiet room with normal ambient sounds. Too loud noises, playing for 14-16 hours per day in their bedrooms, are also damaging to young babies' hearing. We’ve always advised parents to lower the volume on sound machines and place them at least 7 feet away from baby’s bed. We’ve actually been in homes for sleep consultations, where parents have turned on hairdryers or vacuum settings on their sound machines that would definitely make you cover your ears! And would absolutely impact a little one’s hearing over time.

2. Does White Noise Help My Child Sleep By Blocking Sounds?

Barking dogs, garbage trucks, other family members, shared walls…intermittent sounds can disrupt sleep. In the UPenn study, earplugs reduced the impact of intermittent sounds and sleep fragmentation – a good solution for teens and adults, but obviously not our little ones.

We do think in some cases sound machines can be helpful for masking background noises. But it’s also important to consider how our brains habituate, or get used to, sounds. This is why we don’t recommend too much tip-toeing around: we want babies to get used to the sounds of life inside the house. The brain learns that these sounds are normal and they fade naturally into the background, rather than being unusual and startling. Practicing habituation is a wonderful workout for babies’ brains, better than being exposed to monotonous sound for long periods.

3. What If White Noise Has Become My Baby’s Sleep Association

This can be true, but babies and little kids can get used to sleeping in a quiet room too, and that becomes their new sleep association. This is similar to how parents worry about getting rid of sleep sacks or pacifiers, and we’ve seen how babies find their own more helpful sleep associations almost immediately.

We don’t like seeing that REM sleep is affected by pink noise, because babies spend a lot of time in REM sleep – proportionally a lot more than adults – and it’s critical for brain development. In fact the study authors made this connection:

“Overall, our results caution against the use of broadband noise, especially for newborns and toddlers, and indicate that we need more research in vulnerable populations, on long-term use, on the different colors of broadband noise, and on safe broadband noise levels in relation to sleep,” said the lead author of the study, Dr. Basner.

If you’re using a fan, air purifier, or a sound machine on a low volume, it’s probably okay, but the question we have for ourselves and our parents is, why are we doing this? Why has it become expected and ubiquitous? A generation ago, babies slept without a machine producing sound all night long. Today, many parents feel anxious about putting a baby to bed without one. As evidence accumulates, we're increasingly encouraging families to question that assumption.

https://www.pennmedicine.org/news/pink-noise-reduces-rem-sleep-and-may-harm-sleep-quality

https://www.hhmi.org/news/white-noise-delays-auditory-organization-brain

FAQ

Not necessarily. They may be helpful in some situations, particularly with newborns or in noisy environments. However, emerging research suggests parents should be cautious about volume, duration, and whether a sound machine is needed at all.independence — not a problem with your baby or your approach.
It can if it is too loud or placed too close to a baby's sleeping area. Some sound machines are capable of exceeding recommended sound levels. (The long duration most sound machines are used adds to the risk.)(should we move this section or a version of it down to the FAQ, Can white noise damage a baby's hearing?) Research indicates that high-volume or continuous white noise can damage a baby's delicate auditory receptors. Many sound machines exceed safe decibel thresholds, increasing the risk of noise-induced hearing loss, hindering the natural mapping of sounds in the brain, and potentially delaying speech and language development.
Many families find they can gradually reduce or eliminate sound machines after the newborn period, especially once babies become accustomed to normal household sounds.
Fans and air purifiers typically create lower-level background noise and serve another purpose besides masking sound. The key consideration is volume and duration of exposure.

Author Bios

Julie Wright, MFT & Heather Turgeon, MFT

We're Julie Wright and Heather Turgeon — psychotherapists, and authors of the best-selling book The Happy Sleeper.

We're also both moms, so we know what it feels like to be desperate for sleep while also wanting, above all else, what's best for our babies.

We created The Happy Sleeper method to give parents a science-based, developmental approach to healthy sleep and a healthy bond. We’ve helped over 100,000 parents achieve this goal, and we’re excited to help you too!