The problem is electric cars - or to be more precise, hybrids when they are not running on petrol. Apparently, they are too quiet and people keep getting run over. It's not a new problem - in Gas Powered Public Transport: how it all began we recounted the story of a similar problem when a Rolls-Royce powered Gas Bus was developed in the mid 1970s by the then Teesside Municipal Transport in the UK.

And if you can make a bus stop rattling and wheezing its way along a city street, then a modern car, built by robots and using quiet tyres, will for sure creep up on you.

It's a problem that UK sports car maker Lotus has solved.

In May last year, Lotus said "due to the almost silent operation of hybrid vehicles at slower speed when running on electric power, the independent travel of the blind and partially sighted may be put at risk as they cannot hear these quiet vehicles as they approach, making crossing a road or walking through a car park hazardous."

Mike Kimberley, Chief Executive Officer of Group Lotus plc introduced the company's new technology, saying "Our advanced external sound synthesis technology increases pedestrian safety, while retaining the car’s environmental benefits. We hope that legislators introduce minimum noise requirements for vehicles to encourage the adoption of technologies, such as ours, which will ultimately increase pedestrian safety.”

Duncan Vernon, Road Safety Manager, at RoSPA (Royal Society for the Prevention of Accidents) said: “Road safety professionals teach children that they can improve their safety by listening for traffic, and the sound of an approaching vehicle is a warning that most pedestrians will use before making the decision to cross the road. New electric engines make vehicles much quieter, so we need to look at ways of ensuring the safety of pedestrians. We welcome innovative solutions which address this."

The comments from the Japanese government almost replicate the message from Lotus. And new research is to be started to find a way to make electric vehicles noisier.

Lotus is already the leader in noise-cancelling technologies to make cabins quieter: think of those bulky headphones so many of us use on aircraft to cancel out the wind-rush and engine noise.

That works by taking the ambient noise, analysing it, and producing a sound that balances it: a bit like a scales but for sound. When the original noise and the generated noise are opposite and equal, the ears are tricked into thinking that the original noise is no longer there.

What Lotus has done is ingenious: it has taken the sound from an engine when the engine was running normally and reprocessed it. Then, taking data from the engine management system and the road speed, it calculates what noise a petrol engine car would be making at that speed. Then, when the engine is running on electric, it broadcasts the sound through a high quality waterproof speaker at the front of the car. Remarkably, because gaining the original sound samples can be done in a test-bed, the correct sound can be produced for each individual model of car.

So your Nissan won't sound like a Toyota.

Lotus has patented its technology.

Japan might like to pick up the phone. It's not even going to cost them an international call: in October 2007, Lotus Engineering opened an office in Tokyo.