The wonders of modern technology - a car that glides seamlessly along with hardly any noise at all.

Well that's great if you're the driver or the passenger, but today's quiet hybrid cars are not so good for pedestrians as people simply don't hear them coming.

Lotus has decided to create the technology to bring that oh so thrilling sound - the roar of a well tuned engine - to eco conscious drivers.

The car manufacturer explains that its "safe and sound hybrid technology" simulates the growl of a combustion engine, making it "instantly recognisable that the vehicle is in motion".

It has already put the system into a Toyota Prius, which is one of the most popular hybrid cars on the market.

Lotus adds that the device kicks in automatically to produce an artificial engine noise when the hybrid car runs on its electric motor.

But when the hybrid car's combustion engine takes over, sensors fitted to the engine and suspension turn off the sound.

The Independent adds that the engine noise is produced by a waterproof loudspeaker, which is positioned next to the car's radiator, making the sound seem to originate from under the bonnet.

The system produces a pitch and frequency designed to help pedestrians identify the car's speed and distance.

Mike Kimberley, chief executive of Group Lotus, said: "The increased acceptance of greener vehicles such as hybrid and electric vehicles is to be encouraged; they have an important role in improving fuel economy and reducing emissions.

"Our technology increases pedestrian safety, while retaining the car's environmental benefits."