Electric and Hybrid Cars are lauded for their ability to operate while producing far less pollution than their internal combustion cousins, but for some their lack of noise pollution has actually become something of a concern. Some groups, including transportation experts and advocates for the blind fear that pedestrians may fail to hear these vehicles approaching, and that the incidence of vehicle-pedestrian accidents could rise sharply as EV's become more common. Manufacturers are well aware that to address these safety concerns, transportation agencies in the U.S. and Japan may mandate artificial sounds for the vehicles.
As a result, automakers such as GM, Toyota and Nissan are all currently researching sound and sound-production.
Longtime Nissan employee Toshiyuki Tabata, who spent years as the company's top sound-suppression engineer, is now leading the team tasked with creating a distinctive sound for the new Leaf electric sedan. Initially instructed to re-create the sound of an engine, Tabata and his team rejected that idea as backward-looking. Instead, he says, “We decided that if we’re going to do this, if we have to make sound, then we’re going to make it beautiful and futuristic,”
The Nissan team worked with various Japanese composers of film scores, eventually coming up with a high-pitched sound reminiscent of the flying cars in “Blade Runner, Ridley Scott's classic film of a dark, distopian future.
“We wanted something a bit different, something closer to the world of art,” Tabata said, adding that the sound system will turn on automatically when the car starts and shut off when the vehicle reaches 20 kilometers per hour (12 mph). At that speed tire noise and air-flow turbulence begin to make vehicles audible, irrespective of engine noise.
Earlier this year, the Japanese Federation for the Blind submitted a request to Japan’s transportation ministry, the Japan Automobile Manufacturers Association and the country’s carmakers to consider the issue of pedestrian danger from nearly silent EV's. The ministry set up a committee that met in July and August, and will present recommendations by Dec. 31.
Meanwhile, The U.S. National Highway Traffic Safety Administration is analyzing data on crashes involving pedestrians and hybrid vehicles and plans to issue a final report by January. The regulator works with advocacy groups including the National Federation of the Blind, which urged makers of electric cars and hybrids to incorporate noise into their designs. Nissan presented its sound system to the NHTSA on Sept. 3
Car electronics manufacturers, not content to wait for the automakers to present original equipment solutions to this problem, are busily creating aftermarket systems designed to emit "designer sounds". Tokyo-based Datasystem Co. currently sells a device that emits 16 different sounds including a cat’s meow, a cartoon-like “boing” and a human voice saying, “Excuse me.”
Even though regulators haven’t yet formally issued any rules or guidelines, the writing appears to be on the wall. Nissan says that it may move forward pro-actively, equipping the Leaf with its sound system in time for the car’s introduction next year.
According to Tabata, his “beautiful” sound may help sales. “We don’t want to destroy the brand of the electric car,” he said. “We want to have something that will enhance its image.”