For comparison, the “shushing” sounds in utero range anywhere from 70 to 91 decibels, while a vacuum cleaner is typically 70 to 80 decibels. In other words, the womb is not a quiet place! Once born, your little one suddenly finds themself in a disconcerting world of hushed tones and measured steps. Although designed for their comfort, this carefully guarded silence can leave them feeling detached, anxious, and isolated. No wonder your baby may be having trouble sleeping.

Why White Noise Helps Baby Sleep

White-noise machines create a comfortable, womb-like environment that calms infants, encouraging them to stop crying and fall asleep faster. White-noise machines also help babies stay asleep longer. It may seem like it works like magic, but the trick can be easily explained. Ever wonder why your baby seems to sleep for only 20 minutes at a time? As your little dreamer snoozes, they cycle in and out of deep sleep and light sleep, experiencing brief periods of what’s often referred to as “sleep arousal” about every 20 minutes or so. Babies wake easily during these periods of light sleep and become anxious, leading to a premature end to naptime. White noise can help silence your baby’s built-in 20-minute alarm clock by drowning out doorbells, rambunctious siblings, and other potential disturbances during vulnerable phases of light sleep. Should baby begin to stir naturally, the calming drone of the white-noise machine could provide a source of comfort, encouraging them to sink back into a deep sleep.

Buying a White Noise Machine

In 2014, the American Academy of Pediatrics warned against several white-noise machines, citing that anything above 50 decibels could cause damage to a baby’s hearing as well as cause other developmental delays. So before purchasing a white noise machine, be sure you do your homework to ensure your little one’s safety. White-noise machines are available online and in most stores. But if you’re on a budget, white noise is also easy to produce at home, such as by running a fan. You also can pick up a free, white noise-generating app such as White Noise Baby for your smartphone—a great, on-the-go option. Another potential pitfall: Battery-operated machines or machines that only work on a timer. Many babies will wake when their machine stops working, so choose a model you can leave on all night if need be.

Using a White Noise Machine

Now that you’ve settled on the right machine, you’re probably wondering how best to use it. What volume works best? How loud is too loud? You may have to adjust the volume on your white noise machine in order for it to effectively calm down your crying baby. Once your little one has been soothed, adjust the volume to the level of a soft shower. If it seems uncomfortably loud to you, be sure to turn it down, as your little one may be uncomfortable also.