It is unlikely that anyone until quite recently could have thought that such an obvious advantage of electric vehicles, as low noise, would be a serious problem. As has shown practice, cars with low noise level can be dangerous for some groups of pedestrians, in particular, blind and visually impaired.
In this regard, the National Highway Traffic Safety Administration (NHTSA) issued a decree obliging manufacturers of hybrid cars and electric vehicles to equip them by September, 2019 with special additional sound devices warning of the approach of pedestrians and cyclists. And by 2020 all the cars of this group descended from the assembly line should be equipped with such devices.
The NHTSA estimates that additional audio signals can prevent up to 2,400 injuries each year. Electromotorcycles, three-wheeled vehicles, and medium and heavy trucks are exempt from this. This requirement also does not apply to gasoline and diesel cars, which does not look quite logical.
The NHTSA requires automakers to install external speakers that issue simple tonal signals in the parking lot when the car is pulled back and while driving at speeds exceeding 30 km / h.
The sound should be amplified by 3 dB with each speed increase of 10 km / h. Electric cars should produce sounds from 47 to 67 dB. Studies conducted by NHTSA have shown that such a level of noise is completely harmless to humans and animals.