The Infiniti M35h will offer a standard audible pedestrian warning system that uses a range of sounds to ensure people can hear the car coming when it is driving in electric mode, something Infiniti says that car will do as much as half the time it's on the road. The M35h goes on sale in Europe in spring 2011.
Automakers are looking for ways to give their hybrids and electric cars futuristic sounds to ensure that the vehicles don't pose a danger to pedestrians. Unlike gasoline or diesel cars, EVs are almost silent when they start and accelerate to cruising speeds. Pedestrian safety lobbyists and organizations for the blind worldwide are campaigning for legislation to ensure EVs are given a unique sound that can be heard by people outside the car.
The M35h's computer-controlled Approaching Vehicle Sound for Pedestrians (VPS) device links an in-car sound synthesizer with a speaker built into the front bumper. The system works from start-up – when the sound is the loudest – to 30kph (about 19 mph) by emitting a range of high and low sounds at different volume levels. The noise goes from high to low frequency depending on vehicle speed and whether the M35h is accelerating or decelerating. An intermittent tone is used when reversing. The sound ranges from a high of 2.5 kilohertz to a low of 600 hertz, making it readily audible to all age groups, Infiniti said in a release.
This solution was chosen after working with cognitive and acoustic psychologists who study pedestrian behavioral patterns to noise pollution, Infiniti said.