As electric cars become quieter, they likewise become more dangerous to pedestrians who don't hear them. The latest update to the US National Highway Traffic Safety Administration's proposal outlining the minimum sound requirements for hybrid and electric vehicles states that EV manufacturers should offer electric car owners a series of driver-selectable pedestrian alert sounds to choose from for their hybrid electric vehicle (HEV) or electric vehicle (EV).
On Sept 17 the US National Highway Traffic Safety Administration published a proposal to require HEV and EV automobile companies to "install a number of driver-selectable pedestrian alert sounds in each HEV they manufacture." Currently, only one sound is allowed per vehicle; this proposal would remove that limitation.