Lotus Makes Hybrids Sound Like Real Cars

Hybrids are the greatest. They pollute less and consume less than regular cars and save you boatloads of money at the pump. But activists and legislators consider them silent killers that prey on blind people who never hear 'em coming.

Full Hybrids like the ubiquitous Toyota Prius run only on electricity at low speeds, emitting no more than a whine around town. That's great for lowering noise-vibration harshness and making drivers feel like George Jetson, but it's a big problem for the blind -- and pedestrians, and cyclists, and people who simply don't pay attention -- who rely on the familiar rumble of internal combustion to know what's coming down the pike.

The engineers at Lotus, a company way into green these days, have a solution.

Lotus took a bone-stock Prius and outfitted it with a waterproof speaker near the radiator that blares simulated yet realistic engine sounds to let pedestrians -- those who don't have earbuds crammed into their ears, anyway -- know to watch out. "Our advanced external sound synthesis technology increases pedestrian safety, while retaining the car’s environmental benefits," says Mike Kimberley, CEO of Group Lotus.

The system uses a speed sensor on the accelerator to control the vroom-vroom sound. You only hear it as the car approaches, and it cuts out entirely when the car's engine takes over at higher speeds. It's all automated and Lotus says the driver hears almost nothing.


Source: http://blog.wired.com/cars/2008/08/lotus-makes-ele.html

See also: http://en.wikipedia.org/wiki/Hybrid_vehicle