Let’s talk about white noise in general first, and then move on to white noise and babies.
So what is white noise?
White noise is a random collection of sounds between the frequencies of 20 to 20,000Hz.
White noise can be generated by an electric motor, as in the Marpac DOHM or be digitally created, as in the Sleep Easy Sound Conditioner, the Lectrofan or the myBaby SoundSpa.
Many sound machines play lullabies or natural sounds, such as babbling brooks, ocean surf or chirping birds. These are not by definition white noise, although many people include these natural sounds under the same umbrella.
Instead, white noise sounds like a high pitched static noise that you hear when your TV is not tuned in properly.
Why are white noise sounds so popular for sleeping?
There are two groups of people who love white noise and just cannot sleep without it. The first group are people who can’t sleep in a completely silent room and who need a constant sound in the background, to help them relax and drift off to sleep.
Many of these people found that leaving an electric fan switched on all night helped them to sleep and then decided to buy a white noise generator instead, because they are more portable and use less electricity than an electric fan.
The second group of people are those that have difficulty falling asleep and staying asleep, because of household noises or external noises that keep disturbing them.
These people find that a white noise sound generator helps them to relax and blocks out all of these sounds which keep them awake.
White noise or noise cancelling machines help shift workers to sleep during the day, apartment livers to block out the sound of their neighbors, owners to calm sensitive or anxious pets and people to generally mask loud traffic noises, barking dogs and loud music.
For centuries, parents have known that soothing music and lullabies help babies to sleep during both the day and the night.
It is only recently (in relative terms), that technology has given us sound machines for babies, which play these soothing sounds for babies, infants and young children.
As with everything (and rightly so), parents want to make sure that their children are safe, so the safety of these sound machines for babies has come into question.
Is white noise safe for babies?
There are a number of different sound machines for babies – those that play heartbeat sounds, lullabies, ocean sounds (and other natural sounds) and those that play white noise for babies.
It is not necessarily white noise that is a problem for babies and young children, but it is the volume and the duration of these sounds that has been questioned.
There is not a lot of research on the safety of sound machines and white noise for babies, but there is one recent piece of research that stands out and one opinion that is worth listening to.
Research in 2014, published in the journal Pediatrics
Dr. Bale Pepsin who works at the University of Toronto and the Hospital for Sick Children in Toronto, decided to investigate whether the use of sound machines increased the risk of noise induced hearing loss in 6 month old babies (you can read the article here).
To do this Dr Papsin, measured the maximum output levels of 14 sleep machines at 30, 100 and 200 cm distance from each machine. He found that the maximum volume setting for all 14 machines were above the 50 dBA suggested for hospital nurseries at both 30cm and 100cm distance and 13 exceeded this level at 200cm as well.
They also found that 3 of the sound machines were above the 85 dBA recommended levels for noise exposure in adults (if played for 8 hours consistently) at 30cm distance. In addition, 2 of the machines produced sounds at 92.9 dBA and would only need to be played for 2 hours before exceeding the levels recommended for adults.
What does this research mean?
This research appears to indicate that if you play sounds at levels of 50 dBA or above for extended periods of time, it can seriously harm your baby’s hearing.
Therefore this report recommends that parents play these sound machines for short durations only, at low volume and as far away from the sleeping baby as possible.
Opposing these recommendations is Dr Harvey Karp, an assistant professor of pediatrics at UCLA with a private practice in Santa Monica and author of “The Happiest Baby on the Block” and “The Happiest Baby Guide to Great Sleep”.
Dr Karp states that the results of the Toronto study do not justify their recommendations, in particular the recommendation to limit the duration of playing these sounds is not supported by the research – which if you read the article is actually true, because they only hypothesized about the level of the sounds, not the duration.
Dr Karp believes that playing sound machines at more moderate levels for long periods of time has not been shown to be detrimental to baby’s hearing and is a safe and effective tool to help babies settle and sleep.
So what does this really mean – how loud should white noise be for a baby?
There is no hard and fast rule here, but it is only sensible to be aware of that loud noises can impair your babies hearing and to play the sounds from white noise machines as low as possible, adhering to any recommendations by the manufacturers regarding volume, distance from your baby and duration of the sounds.
Best baby sound machines
Not all baby white noise machines will suit all babies, but there a few that are very popular:
Baby Shusher – This baby sound machine was designed by parents and is based on Dr Karp’s methods in his book – “The Happiest baby on the Block” and plays a shushing noise to help soothe and settle your baby.
myBaby SoundSpa – This super little sound machine by HoMedics was designed to be portable enough for use at home and whilst travelling. It is operated by both batteries and mains power, is light weight and very affordable.
Graco Sweet Slumber Sound Machine – If you want a sturdy little sleep sound machine that plays 12 preset sounds and youc an laod your won from your MP3 player, then the Graco SweetPeace is for you. It operates on both batteries and mains power, has a lovely blue night light and has a 60 minute auto shut-off timer.