You have talked about this before, but now the New York Times is in contradiction. They just put out an article referencing studies that say excessive noise (above 30 decibels) is bad for your mental health! I think the studies you reference about white noise say 50 to 70 dB is the sweet spot, so now I’m confused. Am I harming my child by having them sleep 12 hours a night at 56 dB? (I checked with my cellphone meter app — that’s what we’re at.)
—Panicked Mom Who Also Sleeps with White Noise
Panic headlines! They are everywhere.
There are a couple of reasons why you shouldn’t panic or change your white-noise behavior over this.
The first is that the best of the research discussed in this article — the data that is based on lab experiments and so on — focuses on noise variation as a key issue. In terms of disrupted sleep and stress response, a freight train rolling by every couple of hours is much more of a problem than a constant noise level. You can think about this in your own life: the difference between being in a fairly loud room in a continual way versus being in a quiet room and all of a sudden experiencing a loud noise. The latter is going to make you jump and elevate your stress level more.
The second issue is that many of the claims in the article — about the link between noise and, say, cardiovascular health — are based on correlational studies, which are inherently going to struggle to separate noise exposure from other characteristics. People who live in noisy environments, or work in very noisy occupations, tend to have fewer resources. These lower resource levels are strongly linked to worse health for many reasons, and separately identifying the impacts of noise is very challenging.
A final point: Much of the possible reason for a negative impact of environmental noise variation is an impact on sleep — good-quality sleep is associated with better health, and it is reasonable to think that noise disrupts sleep. Consistent white noise for babies, though, has been shown to improve sleep. This is another way to see that white noise at these levels is not the same beast.
If you want to read more about white noise for babies specifically, see this post.