Governments and businesses are already switching to electric fleets. Jim Castelaz, the founder and CEO of Motiv, a California company that manufactures power trains for large electric vehicles, told me that parents now sometimes ask drivers of electric school buses to honk when dropping children off, because they can’t hear the buses coming. (Electric and hybrid vehicles may actually be too quiet; the National Highway Traffic Safety Administration is working on new rules that will require such vehicles to make a minimum amount of noise at low speeds so that pedestrians can hear them coming.)

Even electric vehicles still make noise when they’re speeding along the pavement, of course. But Arizona, California, and other states have begun experimenting with something called quiet pavement, a rubberized asphalt or smooth concrete mix designed to lessen sound. In Phoenix, it cut traffic noise by 6 to 12 decibels, according to Robert Bernhard, the vice president for research at the University of Notre Dame.

2. A Truce on Leaf Blowers

People across the United States have been fighting for years to ban leaf blowers, which are not only loud but also dirty. (As Atlantic national correspondent and noted leaf-blower opponent James Fallows has pointed out, gas-powered leaf blowers with cheap two-stroke engines can spew as much pollution in half an hour as a Ford F-150 pickup does driving across the U.S. one and a half times.) The issue has proved contentious, at times pitting neighbor against neighbor. But technology offers a compromise.

The demand for long-lasting laptops and mobile phones has spurred innovations in batteries, which can now power some of the noisiest devices, including leaf blowers and lawn mowers—making them far cleaner and quieter. Even jackhammers can be made quieter: In 2014, construction crews in New York City started using electric jackhammers, which are reportedly about half as loud as traditional ones.

3. Targeted Sirens

When a fire truck screams down a city street, thousands of people might hear it, even if only a couple dozen need to get out of the way. In a few decades, though, emergency vehicles might send sirens directly to cars’ Internet-connected audio systems and to the phones and smartwatches of pedestrians nearby, Schulze, of the Sound Studies Lab, told me. Emergency signals could be marked high priority, so as to interrupt music or phone calls, he said.

Self-driving cars could virtually eliminate the need for sirens and horns, Raj Patel, the global leader of acoustics at Arup, a design firm, told me. Already, the cars are programmed to drive more conservatively if they detect flashing lights, and in the future, emergency alerts could be sent directly—and silently—to their computer systems. We would still need a way to alert pedestrians and bicyclists, however.