Lotus Engineering, the automotive consultancy arm of Lotus, has developed a system that generates sounds from formally quiet electric and hybrid vehicles.
Such vehicles, a favourite choice of the environmentally conscientious, have recently been criticised by blind and partially sighted people.
That's because, due to their almost silent operation, the blind and partially sighted may be put at risk from the vehicles, since they cannot hear them when they are running on electric power at slower speed, making crossing a road or walking through a car park hazardous.
In Lotus' so-called 'Safe & Sound' system, a waterproof loudspeaker system adjacent to the radiator broadcasts synthesised engine sounds from the front of the vehicle when the hybrid vehicle is operating on the electric motor.
The sound generated is similar to that from a conventional engine, which makes it instantly recognisable, so that its pitch and frequency can help individuals identify the distance and speed of a vehicle.
Lotus recently demonstrated the system on a Toyota Prius, one of the world's most popular eco-friendly vehicles.