We've extolled the benefits of electric vehicles many times, but while electric propulsion brings undeniable advances in driveability, smoothness and, of course, the ability to provide emissions-free motoring, there are a few drawbacks.
Weight, cost and charging times are well known hurdles that EVs will eventually overcome, while - in present-day Australia at least - a reliance on coal-fired infrastructure diminishes the environmental benefits of all-electric cars.
But there's one other issue: pedestrian safety. With EVs able to glide along almost completely silently, there's a very real danger to pedestrians and cyclists in built-up areas.
And that's where the eVADER program comes in.
An collaboration between ten companies and funded in part by the European Union, the eVADER initiative aims to develop a pedestrian alert system that provides an acoustic warning to pedestrians that's less intrusive than a traditional horn.
Japanese automaker Nissan is one of the partners involved in the program, and has this week released a sound clip of the sound that it hopes will reduce the chance of pedestrian impacts with EVs. Listen to it in the video above.
It sounds... spooky. It's very sci-fi, like an alien abduction is about to occur.
However for all its weirdness Nissan says the sound was specifically engineered to quickly get a person's attention without using a harsh noise.
According to Nissan, it's beamed out from its Leaf demonstrator vehicle at a level roughly five decibels lower than than of an idling petrol engine.
Beamed out? That's right. An on-board camera constantly scans for pedestrians, and when one is detected in the path of the car it uses six directional speakers to focus the alert tone at the pedestrian's head. Other road users shouldn't hear a thing.
It's still very much in the prototype stages, but eVADER's system is a novel solution to a tricky problem - and one that you may see in EVs in the near future.
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