Sounds of Safety

The introduction of electric cars (EVs) and hybrids offered a new solution to help improve fuel economy and reduce emissions.

The problem with these vehicles? They’re too quiet.

Compared to vehicles equipped with gasoline and diesel engines, hybrids and EVs make virtually no noise when traveling in reverse or forward at low speeds. According to the National Highway Traffic Safety Administration (NHTSA), this lack of noise has made electric and hybrid vehicles 20 percent more likely to be in a collision with a pedestrian than one with an internal combustion engine. Additionally, NHTSA says each year about 2,400 pedestrian injuries can be prevented in the United States if all hybrids on the road are equipped to make noise.

Our engineers set out to solve this problem in 2012 by developing a technology that creates noise in these otherwise silent cars. Aptiv calls it a vehicle sound generator. Our AUTOSTAR compliant single-box solution uses software algorithms for multitrack mixing,  pitch shifting and amplitude scaling in relation to vehicle speed. That means, the volume created is automatically programmed to be heard at the best level - lower or higher – based on speed. Basically, the vehicle sound generator creates artificial noise audible to pedestrians when the car is too far away to be heard but when the speed is high enough the air or wheel noise becomes audible and the volume is turned down.

Designed to have limited impact on the vehicle architecture, this technology has low-power consumption critical for EVs and hybrid vehicles, and can also  withstand the harsh environment under the hood.

Today, more than 500,000 Aptiv vehicle sound generators are on the road. The result? Helping to improve safety and prevent injuries.