The daily mode noise power from a station in Los Angeles over the past month. Graphic by Celeste Labedz

Just after the start of our pandemic home confinement, I took one of my last walks around the Unity park, longing for summer, when maybe this too will be past. On the back stretch near the lake, I was hearing birds, mostly chickadees and at least one loud-mouthed blue jay. Not all that unusual, of course. But more constantly, and clearer. Then as I started up the little steep grade by the woods, I realized what was different. The background hum was gone. The airwaves were empty of rumbling, roaring, whooshing, wandering, invisible noise. It was quiet.

It’s pretty easy the past month or so to wonder whether you’re not losing your mind. But that quiet was real.

It turns out that seismologists who spend their days listening to the Earth for signs of tremors and quakes have noticed pronounced downturns in noise levels during the pandemic.

The first scientist to notice it, or to talk about it publicly at least, was in Belgium. In London, scientists reported they were clearly detecting magnitude 5 earthquakes halfway around the world, which in normal times are so obscured by intervening noise that it’s difficult to sort them out. A Caltech graduate student in geophysics posted a Twitter graphic showing that noise levels in Los Angeles plunged from their normal levels in the middle of March. Scientists who routinely monitor noise in Boston found the roar in Kenmore Square went from its usual approximately 90 decibels to under 68 decibels.

What’s happening is that cars, trucks, trains, planes and other ground-shaking activities have for all practical purposes ceased during the pandemic. This has resulted in the diminishment of relentless, human-induced worldwide earthquake (so to speak). Not just in urban areas, but in all probability practically everywhere. Even in the rural village of Unity there is, apparently, less noise. And clearer birdsong.

It is a well-established, if little-known, scientific fact that sound plays a significant role in your mental health. Some people are more sensitive than others. But all along a spectrum, sound can do everything from soothe your mood (when amenable music plays), to wreck it (when aircraft take off), to quite literally induce illness. Grating noise creates stress, and stress gets expressed biochemically in your body, reducing the effectiveness of your immune system, and worse. This is not a guess by sociologists; it’s a carefully researched scientific fact. A dog barking in your neighborhood day in and day out is not just an annoying concentration-wrecker; it can corrode your health. As your mind goes, in general, so goes your body.

This has been known for a long, long time. Barking dogs have been a source of conflict and tension in human settlements for thousands of years. And then there is the subtle, mysterious fact that when the music hits, you feel no pain, to quote a musician who knew. I can well believe that the trigger of creation was a voice. It’s in the birdsong.

The pandemic quiet, it turns out, provides relief to my longing.

Dana Wilde lives in Troy. You can contact him at naturalist1@dwildepress.net. His recent book is “Summer to Fall: Notes and Numina from the Maine Woods,” available from North Country Press. Backyard Naturalist appears the second and fourth Thursdays each month.