Nissan has added sound so pedestrians know the Leaf is coming

Nissan has added sound so pedestrians know the Leaf is coming

Nissan is unveiling the new ‘noise’ it has created for its Leaf electric car. It has invited nearly 500 people to drive its new EV at the company’s Oppama test track in Japan over the next week.

Media, shareholders, government officials, analysts and some of the first customers to place reservations for the EV will be getting behind the wheel of the car for an exclusive world first drive when they will hear the 'approaching vehicle sound for pedestrians' system, which also will be used in the Fuga hybrid expectd on sale this autumn.

Nissan has been continually refining the Leaf ahead of October’s start of production, including what noise it should make to warn pedestrians of its approach. The system is the first of its type to be introduced by an automaker though others have been considering it for hybrid models that can operate on electric power alone.

Nissan said it had developed a set of distinctive sounds after studying behavioural research of the visually impaired and working with cognitive and acoustic psychologists.

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 - the sound system will make sweeping, high-low sounds. For instance, when the car is started, the sound will be louder, so pedestrians are aware of it. When a car is in reverse, the system generates an intermittent sound. The sound system ceases operation when the vehicle exceeds 30km/h (20mph) and enters a sound range where regular road noise is high. It engages again as the EV slows to under 25km/h.

The system is controlled through a computer and synthesiser in the dash panel and the sound is made by a speaker in the engine compartment. A switch inside the vehicle can turn the system off temporarily – it automatically turns back on at the next ignition cycle.