Could a Sound Machine Hurt My Baby’s Growth?

My baby wasn’t following her growth chart at her four-month appointment, and the only question our pediatrician asked upon seeing this was, “Does she sleep with a sound machine?” I told him that yes, we in fact do, since I have a very loud toddler who would make the baby’s naps difficult. He suggested that we stop using the sound machine and we will see “tremendous growth at her six-month appointment.”

Of course I freaked out and spent every possible moment for the next 24 hours scouring the internet for more data to support this. So far, nothing has come up. So am I ruining my baby’s growth by using a sound machine? And if not, should I switch pediatricians?
—Looking for sound advice

I’ve written about sound machines before. The primary concern with these is noise exposure — if the machine is very loud, it could affect hearing. At typical levels, it does not, and there are ways to check the level of your machine (there’s an app on your phone).

There is absolutely nothing in this literature, however, that points to sound machines being related to lower infant growth. The only paper I could find on this (a randomized trial with NICU babies) found that white noise caused significant additional weight gain in preterm infants. That’s the opposite of what your pediatrician is telling you.

You should get a new pediatrician. A fall-off on the growth chart could be nothing, but it also might be a sign of something you’d want to get ahead of. By suggesting an explanation that cannot possibly be right, your pediatrician is getting in the way of dealing with any actual problem.