General Motors is testing a noise emitting device on its Chevrolet Volt aimed at warning pedestrians, particularly the blind, of its presence.
Noise emitting devices on near-silent electric cars and hybrids are not a legal requirement, but GM is keen to install such a system on the Volt. At a recent test Milford Proving Grounds in the US, GM tested the progress of its system in an experiment involving visually impaired people.
Volt engineers have used the car's horn to emit a series of warning chirps when a pedestrian is in proximity of it, evaluating the nature and level of the warnings to alert pedestrians rather than startle them.
Andrew Farah, the Volt's chief engineer, said in his official blog: "A recent report from the National Highway Traffic Safety Administration (NHTSA) demonstrated that the silent operation of low-speed hybrid vehicles is an issue for all pedestrians, not just the blind. In certain situations, electric or hybrid vehicles are twice as likely to be involved in collisions with pedestrians.
"Vehicle sound is not noise; it’s an audio cue and information – for everyone. Whether we’re aware of it or not, we constantly rely on our sense of hearing as we go about our daily lives.
"This is precisely why Chevrolet, GM, and the National Federation of the Blind [NFB] are cooperating to identify a safe level of sound to alert the blind and other pedestrians to the presence of low-speed, silent-running electric and hybrid vehicles.
"A few weeks ago, several NFB members recently experienced a demonstration of the pedestrian warning alert on a pre-production Chevy Volt at our Milford Proving Grounds. They evaluated the alert from the front, sides, and rear of the car.
"We will continue working with the NFB and other groups to gather the critical feedback we need to help create an industry standard so that the sound emitted from EVs is recognisable as the sound of an automobile and detectable by everyone
A GM spokesman said the system would be optional on the first-generation car, but any future models would likely to have a more refined version of the technology included as standard.