WASHINGTON (AP) — New hybrid and electric cars are required to make noise when traveling at low speeds so that pedestrians, especially those who are blind or have poor eyesight, will hear them coming, under a new rule released Monday by the Obama administration.

The new rule could help prevent about 2,400 pedestrian injuries a year once all hybrids on the road are equipped to make noise, according to the National Highway Traffic Safety Administration.

Hybrid vehicles use both a gasoline engine and an electric motor. Electric motors, however, make very little noise compared to gasoline and diesel engines.

The rule requires hybrid and electric vehicles to make audible noise when traveling in reverse or forward at speeds up to about 19 mph. The sound alert isn't required at higher speeds because other factors, such as tire and wind noise, provide warning.

"We all depend on our senses to alert us to possible danger," said U.S. Transportation Secretary Anthony Foxx. "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 Sept. 1, 2019, to equip all new hybrid and electric vehicles with sounds that meet the new federal safety standard. Half of new hybrid and electric vehicles must be in compliance one year before the final deadline.