Chronic noise exposure is not just a nuisance, scientists say. It’s a health risk.
In fact, mounting research suggests that, as average noise levels climb, so do the risks of overreactions in your body that contribute to cardiovascular disease and other health issues.
For a project on the harmful effects of noise, New York Times journalists used a Larson Davis Sound Level Meter, a professional sound measurement device, to assess noise exposure in communities around the United States. But you don’t need a fancy device to get a sense of your own noise exposure.
Try this website
You can search your ZIP code in an online noise map developed by the Transportation Department. But keep in mind that the map uses 2018 data and accounts only for transport-related noise — and, like all modeled data, it is based on approximations — so it pales in comparison with on-the-ground measurements.
But if you have 15 minutes to spare, there’s a better way to check noise exposure wherever you live, work or gather.
Download this app
The NIOSH Sound Level Meter app for iOS, designed by the National Institute for Occupational Safety and Health at the Centers for Disease Control and Prevention, was developed by acoustics engineers and medical experts to help workers prevent hearing loss, but its measurements are just as helpful for detecting systemic risks.
The app’s accuracy was verified in an acoustics laboratory and published in a scientific journal. Note that it measures sound energy — it does not record or share audio.
(The app isn’t available on Android devices, developers said, because the fragmented Android device marketplace made it too difficult to verify the app’s accuracy in the lab. There are other apps available — like Decibel Pro, SPL Meter and Decibel X — but those were not developed at the C.D.C.)
Record a 15-minute average
When you open the app, you’ll see noise levels immediately in large numerals. But, by pressing the “play” icon, the app will begin to collect measurements over time. Leave the app open for several minutes — the “Total Run Time” line tracks how long it has been collecting sound readings.
When it comes to interpreting your sound exposure, the decibel figure on the “LAeq” line will be the most useful. It shows the average sound pressure over the given time period — and if you ran the app for a full 24 hours, the metric would be comparable with the metric used in many studies.
A 15-minute recording is likely to represent the average noise exposure for the hour, said Edmund Seto, an associate professor of environmental health at the University of Washington who is studying noise across America. If you aren’t using a calibrated external microphone for optimal readings — and we assume that you’re not — the developers say running repeated tests in the same space should offer you a representative sample.
Be sure to press the “reset” button — the one with the return arrow — between tests. A more detailed user manual can be found here.
What those numbers mean
The health risks of noise exposure can be hard to interpret since they differ based on source and sound qualities.
As a general rule of thumb, the World Health Organization considers average road traffic noise levels above 53 decibels and average aircraft noise levels above 45 dB to be associated with adverse health outcomes, though their metrics are weighted slightly differently than the average on your screen.
Nighttime noise is considered particularly harmful because it can fragment your sleep and prompt a stress response, even if you don’t remember waking up. The W.H.O. has long recommended less than 30 dB of nighttime noise inside your bedroom for high-quality sleep.
How to protect yourself
Without major regulatory changes, outside noise levels are unlikely to change. Still, health experts say you can take some steps to protect yourself.
Replace old windows with double-pane glass. You can apply foam insulation to noisy rooms — like those with whirring clothes dryers — to reduce their noise emissions.
When it comes to nighttime noise, it’s best to sleep in rooms as far away from the roadway as possible and to invest in heavy window drapes and thick rugs to reduce vibration.
Buy yourself some earplugs, too.
Contribute your findings to research
If you’d like to help researchers improve their noise models, add your measurements to the Noise Across America study portal at the University of Washington. Dr. Seto is eager to hear from you.