Silent is deadly? Leaf getting artificial sounds for safety

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Silent is deadly? Leaf getting artificial sounds for safety

Postby Eikon » Fri Jul 16, 2010 7:22 am

Would you prefer your Leaf to be as quiet as possible, or would you rather have a little artificial noise to let people know your coming.. for everyone's safety?

I'm sure anyone who's interested in hybrid or electric cars has heard talk that they are dangerous and lead to more pedestrian accidents. The theory is that since they often operate with no running engine, they don't make the noise that comes with an engine and exhaust. That silent operation allows the hybrid or pure electric car to "sneak up" on pedestrians who don't hear them. I haven't seen actual statistics, but apparently the ratio of car - pedestrian accidents has been higher with electric vehicles.

Nissan has a solution to this problem...

Artificial noise!

"Nissan has developed an "Approaching Vehicle Sound for Pedestrians" system. The system makes it easy for those outside to hear the vehicle approaching, but the sounds do not distract the driver and passengers inside. Thus, the needs of pedestrian safety, as well as driver and passenger comfort, are met. The sound system is the first of its type to be introduced by an automaker.

While silence is golden, it does present practical challenges. In response to public concern that quiet EVs and hybrids can surprise pedestrians and the visually impaired as they approach, Nissan has developed a set of distinctive sounds that will come standard with Nissan LEAF to ensure a positive experience for drivers, passengers and pedestrians alike.

In developing the sound system, Nissan studied behavioral research of the visually impaired and worked with cognitive and acoustic psychologists. After looking at applied original technology developed to reduce vehicle noise and conducting tests in Japan and abroad, the Approaching Vehicle Sound for Pedestrians system was created.

The sine-wave sound system sweeps from 2.5kHz at the high end to a low of 600Hz, an easily audible range across age groups. Nissan worked to avoid a sound range that would add unnecessary noise to the environment (around 1,000Hz).

Depending on the speed and status (accelerating or decelerating) of Nissan LEAF, the sound system will make sweeping, high-low sounds. For instance, when Nissan LEAF is started, the sound will be louder, so a visually impaired person would be aware that a nearby car was beginning operations. And when a car is in reverse, the system will generate an intermittent sound. The sound system ceases operation when Nissan LEAF tops 30km/h and enters a sound range where regular road noise is high. It engages again as Nissan LEAF slows to under 25km/h.

The system is controlled through a computer and synthesizer in the dash panel, and the sound is delivered through a speaker in the engine compartment. A switch inside the vehicle can turn off sounds temporarily. The system automatically resets to "On" at the next ignition cycle."


- ... technology

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Re: Silent is deadly? Leaf getting artificial sounds for sa

Postby wingFeather » Fri Jul 16, 2010 7:51 am

This is good news. I almost got hit by a Toyota hybrid while crossing the street.

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Re: Silent is deadly? Leaf getting artificial sounds for sa

Postby sultan » Fri Jul 16, 2010 9:22 am

my parent's prius must be defective because it's super loud, you'd have to be deaf to step out in front of it.

i think people get hit by hybrids/electric cars because they don't sound like regular cars, not because they're too quiet. the cars aren't the problem, it's the people.

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Re: Silent is deadly? Leaf getting artificial sounds for sa

Postby retrodog » Fri Jul 16, 2010 10:39 am

I've had a Vectrix for almost two years now. The only near misses that I've had with pedestrians were in parking lots. I can weave in and around them on the Vectrix but I had one guy switch directions and step right in front of me. It scared the holy be-jesus out of him. No contact though.

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