THE SOUNDS OF SILENCE

Image via WikipediaShould the Sound of Silence Be a Bird's Tweet or a Jet's Roar?
To Make Quiet Electric Cars Safer, Engineers Bring Out Bells and Whistles

DETROIT—If a car zips through a forest, and there's no gasoline combusting under its hood, would it make a sound? Normally, no.
But in a few years, the government will require electric cars and gasoline-electric hybrids to emit some type of noise at low speeds, when their battery-driven motors usually run silent. The promised rules—aimed at making the vehicles safer for vision-impaired pedestrians and others who rely on aural cues—have launched auto makers on a quest for the perfect sound. (click below to read more)

The new electric cars are nearly silent, and that's a potential hazard for pedestrians who are blind or visually impaired. The Nissan Leaf has added sounds for when the car starts up and accelerates, or backs up. WSJ's Mike Ramsey reports.
Among those considered: noises reminiscent of jet engines, bells, birds, flying saucers and revved-up sports cars.
In developing their electric car, the Leaf, Nissan Motor Co. marketers initially saw the false-sound feature as a branding opportunity, a chance to create a distinctive sound, like a Jetsons jet pack, that would identify an approaching vehicle as a Leaf.
But a point man on the project, 49-year-old Nino Pacini of Grosse Pointe Woods, Mich., had to rein them in.
"We've had the sound of an internal combustion engine for 100 years," says Mr. Pacini, who has been blind since he was 23 and teaches others how to get around without sight. "And it's fine."
The near-silence of a battery-powered car is a point of pride for many hybrid drivers, an illustration of its ability to run at speeds of 40 mph or more without burning fossil fuel. The quiet ride has been a marketing point for auto makers, who spend millions on insulation and sound-damping technology to make cars quieter.


It has been used for comic effect, too, such as in an episode of "The Office," where the volatile Andy Bernard, driving a Prius at low speed, sneaks up on his romantic rival and pins him gently against a hedge in the Dunder Mifflin parking lot.
But for visually impaired people, it's no laughing matter. A study authorized by the National Highway Traffic Safety Administration in 12 states showed a 50% higher rate of accidents involving pedestrians for hybrids than for standard internal-combustion vehicles. The agency is crafting regulations that will require sounds on battery-powered vehicles by the end of 2016.
For its Volt, which currently has a warning bell that can be activated by the driver, General Motors Co. is considering options for a continuously broadcast sound. "You need to recognize that the sound is a car," says Doug Moore, a senior project engineer for GM. "It can't be things like ring tones or bird chirps."
Toyota Motor Corp. began working on sounds for its hybrids five years ago, initially looking at using the vehicle's horn, having it tweet or make short toots at low speeds, "but you can imagine that might become annoying," says Daniel Smith, a Toyota engineer.
Last month, the company presented its noise at a gathering of the National Federation of the Blind in Orlando. The sound is a hum, but Mr. Smith says, "I've heard people say, it's like, 'Beam me up Scotty'."
Ford Motor Co., which will introduce a fully electric Focus compact next year, is allowing the masses to choose its sound by voting on a Facebook page. Ford doesn't describe the noises, but the four finalists sound, roughly, like an alien spacecraft, a "Star Trek" tractor beam, a muffled jet engine and a normal gasoline engine.
Commenters are lending an ear. "'C'! it's super futuristic but has a nice low frequency component that (to me) is distinctly automotive," said one. The company won't say which sound is pulling ahead.
As with many automotive features these days, "people would like to customize it—one day it would sound like a car, and one day it would sound like a horse," says Dave Finnegan, marketing manager for electric vehicles at Ford. But the goal is that people "can identify that a vehicle is coming."
Sports-car maker Porsche AG found a way to make its electric car both detectable and recognizable, giving the Boxster E prototype the same throaty growl—projected through a speaker—as the gasoline-powered version of the roadster.
"A lot of people buying sports cars like that sound," says Dave Engelman, a spokesman for Porsche.
For the Leaf, Nissan engineers employed a Hollywood sound designer and got help from researchers at Vanderbilt University School of Medicine, who analyzed a hundred sounds—mechanical to ethereal, whistling to bells and rings—in search of combinations easiest to detect.
Mr. Pacini and other blind volunteers, working with the Detroit Institute of Ophthalmology, met with Nissan engineers last year to give feedback.
"They had a sound engineer trying to pick a cool sound for us," Mr. Pacini says. "His idea of the sound was more like a Jetsons jet pack. That's too high of a pitch, and as you get older you lose ability to hear high-pitched sounds. And most visually impaired people are older."
Nissan engineers had to be concerned about drivers' reactions as well. "If it became frustrating to the driver, they could cut the wires to the speaker," says Heather Konet, an engineer with Nissan.
In the end, Nissan developed a sound with two main frequencies they call "twin peaks," that will be broadcast from a front-facing speaker mounted in the engine compartment.
The whistling sound shuts off at around 19 mph. Above about 12 mph, tire noise typically becomes loud enough to be heard.
For now, Mr. Pacini is fairly happy with the results. He points out there is no rear-facing speaker to indicate that a car has gone by, another cue blind people rely on to orient themselves. "What they came up with is pretty good," he says. "Not perfect, but pretty good."
And, he adds, the extra sound will help a lot of sighted people as well, including those too consumed with their cellphone conversations to check for traffic when they step off the curb.
"Blind people don't talk on the phone and walk," Mr. Pacini says.