SEATTLE, Wash. — Adding sound to electric cars will make them safer for pedestrians, according to new research. While reducing sound pollution, researchers with the Acoustical Society of America say electric vehicles are so quiet that can actually create safety concerns for the visually impaired and the blind.
To address this, manufacturers are adding artificial sounds to electric vehicles. 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.
Michael Roan from Penn State University and Luke Neurauter from the Virginia Tech Transportation Institute worked with a team of researchers to test how well people detect electric vehicle sounds in terms of these requirements.
Adding sound still isn’t a perfect solution
The study’s participants sat adjacent to a lane of the Institute’s Smart Road Facility and had to press a button after 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.
“All of the cases had mean detection ranges that exceeded the National Highway Transportation Safety Administration minimum detection distances. However, there were cases where probability of detection, even at close ranges, never reached 100%,” Dr. Roan says in a media release.
“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 explains that further studies are still necessary to investigate sound 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.
The team presented their findings at the 181st Meeting of the Acoustical Society of America.
South West News Service writer Georgia Lambert contributed to this report.