One thing can be said for gas guzzlers — you always hear them coming. Generally speaking, the lower the mpg, the higher the decibels. Which is why electric cars, with a mpg approaching infinity, have a problem: their motors make so little noise you might not hear one coming, and step out in front of it.
Nissan, which plans to sell its all-electric car the Leaf next year in the States, has been experimenting with a “sound system” that creates a noise to warn pedestrians of an approaching car. The system would turn on when the car is started and shut itself off when the car reached 12 miles an hour, at which point the Leaf’s tires make enough noise to be audible.
Inspired by Blade Runner
Toshiyuki Tabata, Nissan’s noise and vibration expert, normally tries to figure out how to make cars quieter. But for the Leaf the goal was to make it louder — only with style. So Tabata and his team consulted Japanese film score composers, and eventually settled on a sound reminiscent of the flying cars in the sci-fi noir film Blade Runner.
“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,” Tabata told Bloomberg News.
A Growing Concern
Nissan is not the only car company working on the issue of sound and the electric car; Toyota is doing the same for the hybrid Prius, which will have an optional plug-in model next year that will rely more on electric power. General Motors, Renault, Ford and others are introducing EVs in the next couple years, so the sound issue will be a growing concern.
In the States, 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, according to a spokeswoman, and the National Federation for the Blind is asking car makers to agree on a minimum standard of noise for their vehicles. The blind, who often rely on their hearing to gauge traffic conditions, children, and the elderly are all seen as at higher risk from silent cars.
Nissan has not decided whether to install the system on the Leaf in time for its US debut.
A Pandora’s Box of Noises
There is also the possibility that with more widespread adoption of electric cars, each driver will choose to install their own engine noise, similar to cell ring tones. But unlike ring tones, having a car that revs up to speed to the tune of the latest Top 40 hit could be a dangerous distraction.
Already, in Tokyo, car owners can buy a device that emits 16 different sounds including a cat’s meow. “There is a risk of these things sprouting up like bamboo shoots everywhere and disrupting the general noise environment,” said Tabata.