Enjoy (or fear) the silence while it lasts. Electric and hybrid vehicles might be too quiet to be heard by pedestrians, posing a specific danger to individuals without sight, even though battery-driven vehicles are touted for their potential to reduce on harmful emissions spewed for decades by gasoline-powered cars.
Although the relatively low number of hybrid and electric vehicles on your way as well as the absence of data to link pedestrian injuries to quiet cars make it challenging to validate these concerns, one option being floated is the one about "car tones" to replace with the missing engine noise, reports The Brand New York Times. The Times cites Nissan, plug, BMW and Toyota-in hybrid maker Fisker Automotive as companies all considering the addition of sounds that would more prominently announce the presence of their cars on the road. (Stories of Fisker’s plans to use speakers to pump out sounds "like something between a Formula One car and a jet plane" surfaced in March 2008.) "One possibility is choosing your very own noise," BMW told the Times.
Congress, already considering the possibility that too-quiet cars could be dangerous to pedestrians, has versions of The Pedestrian Safety Enhancement Act of 2009 within the House and Senate that would direct the Transportation Secretary to study and establish a motor vehicle safety standard that gives for a means of alerting blind and other pedestrians of motor vehicle operation.
The most persuasive argument in favor of noisier hybrid and electric vehicles came just last year via a study led by University ofRiverside and California, perceptual psychologist Lawrence Rosenblum, who asked blindfolded subjects to listen to recordings of cars approaching at five miles per hour. As reported in the August 2008 issue of Scientific American, subjects could hear the hum of a Honda Accord’s internal-combustion engine 36 feet away. But they neglected to identify a Prius, running in electric mode, until it came within 11 feet-affording them less than two seconds to react ahead of the vehicle reached their position.
The noise added to hybrids wouldn’t need to be particularly loud, Rosenblum said, given the human brain’s extreme sensitivity to approaching sounds relative to those that are fixed or moving away. Approaching sounds most readily stimulate regions of the brain associated with motor action, because the former will probably pose a threat. Whether it’s a great idea to give drivers a selection of sounds to choose from is an open question. Shouldn’t a vehicle sound like…a car?