Are hybrid cars dangerously quiet?

Toshiyuki Tabata spent 30 years as a Nissan Motor engineer trying to make gasoline-powered cars quieter. Now he's consulting music composers to make electric cars noisier — and safer.

Electric and hybrid cars, with little or no engine noise, are lauded for their silence, yet some groups including advocates for the blind say pedestrians may fail to notice them approaching. To address those safety concerns, transportation agencies in the U.S. and Japan may mandate artificial sounds for the vehicles.

"We fought for so long to get rid of that noisy engine sound," said Tabata, Nissan's noise and vibration expert. "With electric cars, we took a completely different approach and listened to composers talk music theory."

Carmakers including Nissan and Toyota Motor, manufacturer of the Prius gasoline-electric hybrid, are researching sound as more silent models come to market.

Nissan will start selling its Leaf electric car next year in the U.S., Japan and Europe, while General Motors plans to introduce its Volt plug-in electric car by November 2010. Toyota will introduce a battery-powered vehicle in 2012.

Tabata was instructed about three years ago to re-create the sound of an engine. Given his years of work eliminating noise to enhance the driving experience, he said he balked at the suggestion of turning back the clock and adding anything evocative of an engine.

"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 said.

The company consulted Japanese composers of film scores. What Tabata and his six-member team came up with is a high-pitched sound reminiscent of the flying cars in "Blade Runner," the 1982 film directed by Ridley Scott portraying his dystopian vision of 2019.

"We wanted something a bit different, something closer to the world of art," Tabata said.

The sound system would turn on automatically when the car starts and shut off when the vehicle reaches 12 mph, Tabata said.

At higher speeds, electric cars generate tire noise and the engines in gas-electric hybrids kick in, said Takayuki Suzuki, a spokesman for the Japan Federation of the Blind.

While no serious injuries have been reported in Japan, Suzuki said a hybrid car he didn't hear approaching once ran over his cane while he crossed a Tokyo street.

"This isn't just an issue for the blind," Suzuki said. "There's also a danger to children and the elderly."

Earlier this year, the federation submitted a request to Japan's transportation ministry, the Japan Automobile Manufacturers Association and the country's carmakers to consider the issue. The ministry set up a committee that met in July and August and will present recommendations by Dec. 31.

Japanese regulations say cars can't be equipped with devices that emit sounds that could be mistaken for a horn.

The U.S. National Highway Traffic Safety Administration also is analyzing data on crashes involving pedestrians and hybrid vehicles and plans to issue a final report by January, spokeswoman Elly Martin said. The agency 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 agency Sept. 3, Tabata said.

Car electronics manufacturers also developed noisemakers. Tokyo-based Datasystem makes a device selling for $140 that emits 16 different sounds including a cat's meow, a cartoonlike "boing" and a human voice saying, "Excuse me."

"There is a risk of these things sprouting up like bamboo shoots everywhere and disrupting the general noise environment," Tabata said.

Even though regulators haven't issued rules or guidelines, Nissan may equip the Leaf with its sound system in time for the cars' introduction next year, Tabata said. The system will increase the car's sticker price, he said while declining to provide an estimate. Nissan hasn't announced the model's pricing.

Nissan North America has chosen Seattle as one of the first markets to get the Leaf, in October 2010.

The beautiful sound may help sales, Tabata said.

"We don't want to destroy the brand of the electric car," he said. "We want to have something that will enhance its image."