It turns out that we humans are a noisy bunch. Along with all the trash, heat and pollution we produce, we also generate colossal amounts of noise - "anthropogenic noise," it's called - on land from our vehicles and machinery, in the sky from our air traffic, and on the seas from our cruise liners and other commercial vessels.
Apparently amidst the noise of our enginery birds can't hear themselves chirp, whales can't hear themselves sing, animals lay low, and seismic studies have shown that our loud rumbling on the surface makes the earth vibrate beneath us.
But scientists are noting that with the drastic cut in the use of noise-producing machinery, the air all over the world is quieter, the seas calmer, and even the earth has stopped twitching.
Subsequently the birds are singing more softly - though now we may actually be able to hear them better - because they're no longer straining to be heard above the buzz of traffic and machines,
So much calm in the midst of such turmoil.