Starting today, all new electric cars in Europe must by law emit an audible noise. The new EU mandate addresses concerns about the threat to pedestrians from silent vehicles.
The law, which states that a sound must be generated when the car is going below a certain speed, has been generally welcomed. That said, some groups have claimed that it doesn't go far enough to protect fellow road users and pedestrians.
The US isn't too far behind when it comes to noisy electric cars, with mandatory requirements coming in next year. We explain what the EU law changes will mean for car manufacturers (plus what kind of noise you can expect to hear from electric vehicles).
What does the mandatory noise law mean?
As of the 1 July 2019, any new electric cars within Europe must be fitted with a device that makes a continuous noise. The intention is to alert pedestrians to the proximity of the vehicle.
First mooted in 2011 by the European Union, the law has now come into effect, some eight years on. In terms of what form this noise should take, the guidelines from the EU state:
The sound to be generated should be a continuous sound that provides information to the pedestrians and vulnerable road users of a vehicle in operation. The sound should be easily indicative of vehicle behaviour and should sound similar to the sound of a vehicle of the same category equipped with an internal combustion engine.
Things get more complex, however, as there isn't any standardised sound to make. The EU doesn't state that it has to sound like a traditional engine, which has already led to a certain amount of creativity from car manufacturers.
The noise generated must, though, be at least 56 decibles, which is roughly the sound of a normal-volume conversation. A non-electric car on the road can be expected to produce sound at around 70-80 decibels.
While the EU law now makes it mandatory for electric cars to make a noise, some groups, including Guide Dogs for the Blind, don't feel it goes far enough. The law only requests that cars make a sound when reversing, or travelling below 12mph. Faster – and arguably more dangerous – speeds aren't covered.
What will the car of the future sound like?
While everybody can identify the noise of a car engine today, the manufactured sound of electric vehicles isn't determined by physics – just creativity.
Manufacturers can make the noise pretty much anything they want (within reason). Perhaps, in the future, swapping the noise of your car will be as simple as changing your phone's ring tone.
BMW has big plans for the electric car, and intends to unveil up to 25 models by 2023. The brand recently announced that its latest sports car would come with a celebrity-penned soundtrack. The BMW Vision M NEXT has had its ‘engine' noise crafted by none other that Hans Zimmer, whose soundtrack credits include Blade Runner 2049, Gladiator, The Dark Knight and The Lion King.
“Legendary Hollywood film composer Hans Zimmer and BMW sound designer Renzo Vitale designed the boost sound especially for this concept vehicle” – BMW preview statement
The futuristic hum of the Vision M Next would fit right into the Blade Runner universe, and could have drivers thinking that they're about to take to the skies (or off-world?).
Then there's Citroen Ami One Concept, which also sounds like its been ripped from a sci-fi film, with a notably more rhythm melody to its tone. Pedestrians might not so much step out of the way as start to nod their head and tap their toes.
Why do cars have to be noisy?
The noise we associate so closely with cars was never intentional by design. Sure, more powerful engines have made engine roar synonymous with power and performance, but it's a happy accident that cars since the Model T Ford onward have effectively included an audible built-in warning system. It's proved a great alert for pedestrians for over a century to be aware and check their surroundings.
The problem with electric cars, of course, is that they are incredibly quiet. While their dependence on electricity as a fuel means they're less of a threat to the planet, ironically, pedestrians could be left in more danger. Groups, including the UK's Guide Dogs for the Blind charity, have campaigned hard to have manufacturers to emulate a traditional car noise, to give nearby pedestrians a signal that a car is approaching. Dubbed the acoustic vehicle alert system (Avas), car makers are now installing external speakers to their cars that generate a specific sound.
It's not just pedestrians who will benefit. According to research by Jaguar, drivers prefer the sense of feedback that comes from the Avas, over silence, stating that driving is more fun with it on. Some cars will play the noise in the cabin, as well as outside, purely for the benefit of the driver.
In the US, the National Highway and Traffic Safety Administration is mandating that all electric and hybrid cars must emit warning sounds when travelling below 18.6 mph by 2020.