The Infiniti M35h (earlier post), aka Nissan Fuga Hybrid in Japan - 日産フーガ ハイブリッド, will become the world's first hybrid to feature an audible pedestrian warning system as standard when it goes on sale in six months’ time in Europe.
"The new Approaching Vehicle Sound for Pedestrians (VSP) system – is computer controlled and links an in-car sound synthesiser with a speaker built in to the front bumper. It automatically works from start-up to 30 km/h, cutting back in at 25 km/h as the vehicle slows.
Instead of just a single tone, a range of high-low sounds at different volume levels was chosen after an extensive research programme to find the most effective, but least intrusive, noise. The team developing the system in Infiniti’s parent group worked with cognitive and acoustic psychologists studying areas from pedestrian behavioural patterns to noise pollution.
The result is a sine-wave sound that extends from 2.5kHz at the high end to a low of 600Hz. It is a range readily audible to all age groups while avoiding a sound range (around 1,000Hz) that would add unnecessary noise to the environment.