And then there are the birds — so many birds, who all seem so much louder. In fact, it’s likely that they’re actually quieter now than before the pandemic. They no longer have to sing louder to be heard over the racket of the city, a behavior, known as the Lombard effect, that has been observed in other animals, too.

— The Coronavirus Quieted City Noise, Quoctrung Bui and Emily Badger in The New York Times