Should I use a sound machine in my baby or child’s room? (Part one)
(Read part 2 here)
I was seven years old and super excited because my dad was taking me to the big boat show at the convention center – just the kind of thing he and I loved. To this day, though, what I remember most vividly is not the boats, but my dad, fishing a tissue out of his pocket, tearing it into small shreds and instructing me to stuff them in my ears. It was too loud in there, he told me. My parents were both physicians and my siblings and I were taught from an early age to protect our hearing, because hearing damage is permanent.
What does the boat show and my dad’s tissue shreds have to do with sound machines for babies? Well, his concern for my hearing as a young person was spot on. Ears are sensitive, and hearing damage is permanent. Which brings us to the topic of sound machines – a staple of most babies' bedrooms these days.
Are sound machines too loud to be safe?
Unfortunately, yes, many commonly used sound machines and other baby devices can be far too loud to be safe.
The American Academy of Pediatrics recommends only using sounds that measure 50 decibels or less and placing your sound machine at least 7 feet from your baby’s head. There’s a scarcity of research on safe sound levels for babies, so medical experts recommend erring on the side of caution to protect babies’ delicate ears. As a reference, according to the World Health Organization, hospitals shouldn’t exceed 40 decibels at night, and 30 decibels during the day. Long-term exposure in adults to noise exceeding 65 decibels has been correlated with heart disease. According to the CDC, noise exposure in adults of 80 to 85 decibels for over 2 hours can damage hearing.
Turn your sound machine up to a medium or high volume, measure decibels (you can use a decibel counter on your phone – we used the Decibel X app), and most of you will find out that your own sound machines go too loud to be safe.
To help you sort out how to use sound machines in your home, here are some myths and facts about white noise, the brain, hearing, soothing, and sleep:
Myth
All babies and toddlers need white noise to sleep well.
Fact
When used at safe decibel levels, sound machines can be helpful for very young babies — allowing them to calm down and fall asleep faster. This is especially true in the fourth trimester (ages 0-3 months) when babies’ circadian rhythms and sleep centers in their brains are still immature, causing sleep to be challenging and erratic. During these early months, babies often need help falling asleep and sound machines can be one piece of that puzzle. The sounds can induce a calming response and are thought to mimic the sounds heard by baby in utero.
After about the age of 3-4 months, however, sound machines become less potent. The calming response fades and babies no longer benefit from womb mimicking noises. At this age, sound machines can be used to muffle loud and sudden background noises (think garbage trucks, ambulance sirens or barking dogs) and to be part of a bedtime routine, cueing baby that sleep is near.
Older babies and toddlers (5 months and older) don’t need sound machines for good sleep. Their circadian systems are nearly mature and they are capable of self soothing. Their sleep is more organized, predictable and stable and therefore, independent. Their sleep function is strong and hard-wired and no longer needs the extra help. In fact, we don’t want you to be afraid to wean your older baby off of using a sound machine. Don’t worry, if they are solid, independent sleepers, it shouldn’t faze them and might be healthier in the long run.
[Need help developing independent sleep skills and supporting your baby to sleep through the night? See the online class for babies 4-24 months]
Myth
Sound machines created for babies must be safe for their hearing.
Fact
A 2014 study published in Pediatrics, tested 14 white noise machines made for infants and found that all 14 devices exceeded the 50-decibel limit for babies when placed about a foot away from the baby. The study concluded that white noise machines should only be used at decibel levels of 50 or lower, and placed at least 7 feet away from the baby’s bed—never in the crib or on the crib rail.
The Snoo, for example, has built-in, constant white noise that can’t be turned off unless you turn the entire device off, turning it into an ordinary bassinet. Its baseline decibel level is between 65 and 70 decibels and it’s positioned at the baby’s ear. When the baby is very upset and crying loudly, the Snoo raises the sound level to 86 decibels. Understandably, these decibel levels are of concern to parents, pediatricians and sleep specialists like us.
Myth
Shushing very loud into a baby’s ear is good for them.
Fact
Again, the risk of permanent hearing damage is the main concern. This practice can easily go over the limit for babies’ vulnerable ears. We don’t recommend trying it out on anyone because it can be quite painful. Making a shushing sound from a distance can be soothing and calming and safe. Again, Heather pulled out her trusty decibel counter and shushed into it. 70 decibels for a moderate shuuuush and 80 for a loud one.
Myth
Sound machines help babies and little kids sleep better
Fact
Research points to the many benefits of silence on health, including the fact that most people sleep best in a quiet room. Ongoing studies are exploring whether noise throughout the night is the optimal environment for the brain and sleep. The brain has to constantly process and try to make sense of incoming sounds, which can be alerting and may distract from all the other important tasks it needs to do at night.
Myth
Babies can’t sleep if they hear their parents talking and moving around.
Fact
As babies mature, their brains, when given the opportunity, can become used to background sounds. This is called habituation and occurs when we’re exposed, over time, to the normal sounds of life - parents walking around and talking, street traffic and even louder noises like lawn mowers, barking dogs and doorbells.
Ironically, one aspect that can make sleeping while traveling more difficult is the absence of our normal background noises. How many of us remember falling asleep to our parents’ voices, footsteps, maybe the sound of the shower or the dishwasher whirring?
Parents, understandably, are often terrified of anything that might wake their sleeping baby, but it’s good to know that sleep isn’t as delicate as you might think. This habituation takes time, so gradually lowering the volume on your sound machine is a smart way to weather the transition if you choose to phase it out. A low level noise like that from a fan or air purifier can be the happy middle ground some families settle on. — Julie Wright
Stay tuned for Sound Machines, Part 2, with more practical tips on this important aspect of your baby’s sleep.
References:
https://pubmed.ncbi.nlm.nih.gov/24292324/
https://www.apa.org/monitor/2011/07-08/silence
https://ccforum.biomedcentral.com/articles/10.1186/cc8965
https://www.bose.com/en_us/landing_pages/uchealth-sounds-and-sleep-study-summary.html
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4923834/
https://medium.com/awarenow-io/why-we-need-silence-2362b126b58d
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5784839/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1792397/pdf/archdisch00666-0073.pdf
https://pediatrics.aappublications.org/content/pediatrics/early/2014/02/25/peds.2013-3617.full.pdf
https://www.who.int/pbd/deafness/activities/MLS_Brochure_English_lowres_for_web.pdf