Why adding sound to electric cars makes them safer

By Georgia Lambert via SWNS

Adding sound to electric cars will make them safer for pedestrians, according to new research.

While reducing sound pollution, electric vehicles are so quiet that they have been known to create safety concerns, particularly for visually impaired and blind people.

To address this artificial sounds are being added to electric cars.

In the United States, regulations require vehicle sounds to be detectable at certain distances for various speeds, with faster speeds corresponding to larger detection distances.

Dr. Michael Roan, from Penn State University and Luke Neurauter from the Virginia Tech Transportation Institute worked with a team of researchers and they tested how well people detect electric vehicle sounds in terms of these requirements.

The study’s participants were seated adjacent to a lane of the Institute's Smart Road Facility and they were instructed to press a button upon hearing an approaching electric vehicle.

This allowed the researchers to measure the probability of detection versus distance from the vehicle, which is a new criterion for evaluating safety.

Dr. Roan said: “All of the cases had mean detection ranges that exceeded the National Highway Transportation Safety Administration minimum detection distances.

“However, there were cases where the probability of detection, even at close ranges, never reached 100%.

"While the additive sounds greatly improve detection distances over the no-sound condition, there are cases where pedestrians still missed detections.”

According to the fans, even after adding sound, electric vehicles are typically quieter than the standard internal combustion engines found in other cars.

In urban environments, they would create less sound pollution.

Dr. Roan explained that further studies would be needed to be done to investigate detection when all vehicles at an intersection are electric.

Additive sounds could create a complex interference that may result in some loud locations and other locations with very little sound.

Dr. Roan discussed his methods and the results in the talk, which took place at an Acoustical Society of America meeting held at the Hyatt Regency Seattle until Dec 3.