Sirens and the city (photo: Benjamin Kanter/Mayoral Photo Office)

A beautiful, clear April evening in Manhattan. No traffic, which is down 84% overall in the city, says StreetLight. Out of nowhere a screeching siren pierces the air. Many minutes later an ambulance appears—SeniorCare—blaring a siren that measures 124 decibels, higher than a jet takeoff or a thunderclap, the loudest natural sound on earth. The few people on the street cover their ears in pain as