Nissan got the first chance to show off its new electric car ‘pedestrian audio warning system’ last week as it welcomed nearly 500 people to its Oppama test track in Japan.
The Japanese carmaker invited members of the media, shareholder, government officials, analysts and some of the first customers to place reservations for the Leaf to get behind the wheel of the first production test units in a world-exclusive preview that runs between June 11-19, 2010.
Nissan LEAF officially goes on sale beginning in its home country in December, ahead of its UK on-sale date of March 2011.
Since the all-electric concept vehicle was unveiled last August at the grand opening of the new Nissan Global Headquarters, the company has refined the LEAF for the October start of production.
Among the enhancements to the test units used in the preview includes the ‘Approaching Vehicle Sound for Pedestrians’ system, which also will be used in the Nissan Fuga hybrid, slated for sale in autumn 2010.
The system is designed to make it easy for those outside to hear the vehicle approaching, but the sounds should not distract the driver and passengers inside. The sound system is the first of its type to be introduced by an carmaker.
In addition to reducing air pollution, Nissan LEAF and other electric vehicles (EVs) reduce noise pollution. While silence may be 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 developed a set of distinctive sounds that are now to come as standard with LEAF to ensure safety needs are met.
In developing the sound system, Nissan studied behavioural 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 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 new Approaching Vehicle Sound for Pedestrians system conforms to guidelines set by Japan’s Ministry of Land, Infrastructure and Transport in its report, ‘Measures for dealing with the silence of hybrids and similar cars,’ released in January.
