To make the driving experience more emotionally stirring, some electric cars produce fake engine sounds. The Porsche Taycan Turbo, for example, can be equipped with a $500 Electric Sport Sound package that makes the electric sedan sound more sporty and exciting. This has also inspired automakers to get creative. BMW, for example, has enlisted renowned film composer Hans Zimmer to create unique sounds for its new electric cars like the i4 and iNext.

But there's a more important reason why electric and hybrid cars need to make more noise: pedestrian safety. In the US, car manufacturers now have six months to comply with "quiet car" regulations that require electric and hybrid vehicles to produce alert sounds warning pedestrians when they approach.

According to Reuters, a group representing major automakers including General Motors, Volkswagen, and Toyota had requested the National Highway Traffic Safety Administration extend the original September 1 deadline by a full year.

Instead, the NHTSA has extended the deadline by six months, which the organization believes "strikes a reasonable balance between providing necessary regulatory relief and implementing" the regulations as soon as possible. Automakers urged for the new regulations to be delayed since the shutdown of auto plants in North America during the pandemic has "impacted the ability of manufacturers to fully implement the quiet car rule."

The rules will require automakers to add sounds to electric and hybrid vehicles when traveling at speeds of up to 18.6 mph to help prevent injuries for pedestrians, cyclists, and the blind. Factors such as tire noise and wind resistance eliminate the need for alert sounds at higher speeds according to regulators.

These new regulations are estimated to cost the auto industry around $40 million per year due to the need to add an external waterproof speaker to comply with the new safety laws. However, the benefits of reduced injuries are estimated at $250 million to $320 million annually. The NHTSA estimates that the chances of a hybrid vehicle being involved in a pedestrian crash are 19 percent higher than a traditional gasoline-powered vehicle.