Electric and hybrid-fuel cars will be required to produce noise when traveling at low speeds under a new rule issued by the US National Highway Traffic Safety Administration. This is to prevent these vehicles from injuring pedestrians, especially people who are blind or are visually impaired.

Electric cars, which are growing increasingly popular among manufacturers and consumers, make hardly any engine noise. The only noises they usually generate is caused by wind resistance or tire noises, and that is only at moderate to higher speeds.

The new rule requires all newly manufactured electric vehicles 10,000 pounds or less to make an audible noise when traveling forward or in reverse at speeds 19 mph or less. NHTSA says the sound alert is not required at higher speeds because other factors, such as tire and wind noise, “provide adequate audible warning to pedestrians.” It doesn’t explain what kind of alert automakers use, so whether it’s a fake engine noise or a “beeping” noise will be up the manufacturers of electric vehicles.

“We all depend on our senses to alert us to possible danger.”

“We all depend on our senses to alert us to possible danger,” US Transportation Secretary Anthony Foxx said in a statement. “With more, quieter hybrid and electrical cars on the road, the ability for all pedestrians to hear as well as see the cars becomes an important factor of reducing the risk of possible crashes and improving safety.”

Manufacturers have until September 1st, 2019, to equip their vehicles with the new alert, but half of new hybrid and electric vehicles must be in compliance one year before the final deadline. The mandate is being issued as part of a pedestrian safety law passed by Congress in 2010 and signed into law by President Barack Obama.

Advocates for the blind praised the new rule. Eric Bridges, executive director of the American council of the Blind, said in a statement that it will “make our streets safer for blind and visually impaired Americans,” while Mark Riccobono, president of the National Federation of the Blind, said it “will protect all pedestrians, especially the blind, as well as cyclists.”

Some manufacturers of electric cars have been grappling with the issue of nearly silent electric cars, but not in the interest of protecting passengers. Porsche, for instance, has been working on make its Mission E electric sports sedan noisier to satisfy sports car customers who prefer a growl when they gun the engine. Fiat Chrysler and McLaren are also aiming to inject some artificial engine noises in their electric vehicles.