Lotus Engineering creates fake engine sound for \'dangerously quiet\' hybrid vehicles. Image: Biege Alert/Flickr.
In a move designed to counter the potential road-use dangers associated with the quiet operational output of modern hybrid vehicles, high-performance specialist Lotus Engineering has created a synthesised motor sound for eco-friendly cars that will alert nearby pedestrians and cyclists.
The simulated ‘Safe & Sound’ technology has already been successfully tested by Lotus Engineering, the automotive consultancy division of Lotus, via a demonstration hybrid vehicle that instantly took on the aural guise of a regular road vehicle equipped with a conventional combustion engine.
The exploratory shift towards artificial sound integration has come about after notably quiet environmentally-friendly hybrid vehicles were targeted for criticism by blind and partially-sighted people. Specifically, it is believed that the blind and partially sighted are being put at risk when crossing the road or traversing a car park because they may not be able to hear an oncoming hybrid running on electric propulsion.
“Blind and partially sighted people use the noise of oncoming traffic as a cue for when it is safe to cross a road – if a ‘quiet’ hybrid electric vehicle is approaching then they will no longer have this cue and are immediately put at risk,” explained Clive Wood, Transport Policy Officer for The Guide Dogs for the Blind Association.
“As the leading voice on transport and mobility issues in the visual impairment sector, Guide Dogs believes further research and development is needed to address the issues of identifying 'quiet vehicles' for blind and partially sighted people,” Wood added. “The charity recognises the environmental benefits of these vehicles however more consideration needs to be given to the safety implications to visually impaired pedestrians.”
And Wood’s risk concerns are shared by Duncan Vernon, the Road Safety Manager for the Royal Society for the Prevention of Accidents (RoSPA), who commented that children are taught they can improve their road safety levels by listening, as well as looking, for approaching traffic before deciding to cross the street.
“New electric engines make vehicles much quieter, so we need to look at ways of ensuring the safety of pedestrians,” said Vernon. “We welcome innovative solutions which address this.”
In demonstrating the efficiency of its sound synthesis system, Lotus applied the ‘Safe & Sound’ technology to a standard Toyota Prius, which is recognised as one of the best selling and most advanced hybrid vehicles currently on the road.
The system works by monitoring the actual road speed of the host vehicle and then producing a synthesised representative engine sound through a waterproof loudspeaker fitted close to the vehicle’s radiator panel, which then projects the engine sound in front of the vehicle and creates a believable engine sound that automatically turns on when the driver is utilising the quiet electric motor.
Lotus notes that the extra sound should be barely noticeable to the occupants of the vehicle and will be comparable to the sound of its standard engine.
By emitting an authentic engine sound that is instantly recognisably through its pitch and frequency levels, it is hoped that pedestrians and other road users will be able to accurately determine the oncoming distance and speed of hybrid vehicles without even knowing they're hybrids.
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