Researchers in Norway are developing an “adaptive sound” system to address potential electric car hazards to the visually impaired.
The relative silence of electric cars can cause problems for blind people, who may rely on the sound made by cars to let them know when it is safe to cross the road. Electric cars, particularly when travelling at speeds below 20kph (12mph), produce little to no noise and in some cases electric car hazards cannot be detected by pedestrians until they are one second away from impact. Pedestrians are around 40 per cent more likely to be hit by an electric car than by a conventional vehicle.
After a successful campaign by visually impaired activists to reduce quiet electric car hazards, EU rules to be implemented in July 2019 stipulate that all newly-built electric and hybrid cars must emit a noise when travelling at low speeds, to indicate their presence to pedestrians; while electric and hybrid cars already on the road will be gradually retrofitted with noise-producing devices with a final deadline in 2021.
Debate over the type and volume of sound to be produced to best minimise electric car hazards on the road is ongoing, with early suggestions including tonal sound – which can bounce off hard surfaces, causing confusion about the exact location of the vehicle – and soothing white noise.
Researchers at SINTEF, an independent Norwegian research organisation, have been working to develop sound emitters which will reduce electric car hazards by meeting the new sound requirements. They have been focusing on adaptive sound, a concept whereby vehicles are fitted with microphones which detect the ambient noise level of their surroundings and adjust the volume of the sound they emit accordingly.
SINTEF acoustic research scientist Truls Berge said: “A number of car manufacturers, including Nissan, General Motors and Renault, have shown interest in the results of this project. Norway has the highest density of electric vehicles in the world, so it’s natural that electric car manufacturers look to us with regard to traffic safety and research in this field.”
